Ghent, 1566

Matheus Jacobs scraped his spoon along the side of the wooden bowl, filling it with flakes of dried stew. Once he finished his supper, his visit home would be over and he’d have to start his long ride back to the cathedral.

He turned to the window. The sun was already beginning to set, flooding the wheat field with soft orange light. His father and his oldest brother, Adriaan, were out there somewhere, trying to coax the plants from the barren ground.

Since Adriaan would inherit the family land, the younger boys had to learn a trade. Lukas was already apprenticed to the local blacksmith, and Matheus had assumed that he’d also be sent to work when he turned thirteen next year. But instead of finding him a job with the village baker or carpenter, his mother had arranged for him to serve as an altar boy at Saint Bavo Cathedral in Ghent — a morning’s ride on a proper horse, a half day on their poky mule, Mungo.

“Are you almost ready, beertje?” his mother, Anna, called from the back of the room, where she was tucking baby Greet into her cradle.

Matheus scrunched his face, although he secretly liked it when his mother called him “little bear,” a reference to the dark, curly hair that distinguished him from his blond brothers.

“You need to hurry if you want to get to the city before dark,” Anna said. Matheus looked down to keep his mother from seeing the blush spreading across his cheeks. His hair wasn’t all that set him apart. He was the only one of his brothers who was afraid of the dark — who was afraid of anything, really.

That was probably why he’d been sent to the cathedral instead of being apprenticed. He was an embarrassment. Matheus’s father, Joost, had no patience for his spindly, clumsy son, who could barely haul a full bucket of water without drenching his tunic. He’d seen the shame in his father’s face when Matheus limped home after losing a fight.

Before Matheus could reply, there was a knock at the front entrance. That was odd. The family and their neighbors always came through the kitchen. “Go see who it is, beertje,” Anna called. Matheus lifted the latch and pulled open the heavy door, revealing a tall, slender man in a strange outfit. Instead of a tunic and trousers, he wore a brocade jacket over knee breeches and white silk stockings. At first, Matheus wondered how the man had managed to stay so clean, but then he heard the stomp of a hoof. An elegant carriage pulled by four matching dappled grays had stopped in the middle of the road.

“Is this the Jacobs home?” the man asked. He had a strange accent, and he grimaced slightly as he spoke, as if the foreign words left a sour taste in his mouth.

Matheus nodded.

The man removed a letter from the pouch hanging at his hip. “Are you quite sure?” He raised an eyebrow. “It’s treason to tamper with a message from the king.”

The king? Then perhaps the messenger was looking for another Jacobs family. Surely King Philip wouldn’t have business with his parents.

“Who is it?” Anna’s voice called from behind him. Matheus stepped aside to let his mother pass. “Can I help you?” she asked, wiping her hands on her apron.

“I have a letter for Mevrouw Jacobs,” the messenger said with a note of irritation in his voice.

“I am Mevrouw Jacobs.”

“Mevrouw Anna Jacobs?” he asked, giving her an appraising look. “I have come a long way, and I do not intend to leave His Majesty’s correspondence with some peasant.”

Matheus saw his mother stiffen next to him. She raised her chin. “¿Está de España?” she said in a language he’d never heard before.

The messenger’s cheeks flushed slightly. “I do not speak Spanish, madam.”

“You’re not from the king’s court in Madrid.”

“I took over for His Majesty’s courier in France.”

“Donc, je suis Anna Jacobs. Donnez-moi le lettre, s’il vous plaît.”

Both the messenger and Matheus stared at her wide-eyed. The only people he’d heard speak anything but Dutch were the priests, who chanted in Latin, and the traders at the market. Yet here was his mother conversing in foreign tongues like a queen.

The messenger handed Anna the letter, bowed his head, and then strode back to his carriage. Matheus turned to his mother slowly, half expecting to find that she’d turned into someone else completely. But there she was. The same large brown eyes and rosy cheeks. “What’s going on?” he asked.

“Not here,” she whispered, glancing down the road before guiding Matheus inside and closing the door. She held up the letter and examined the elaborate wax seal. Instead of the royal coat of arms he’d seen emblazoned on proclamations and flags, there was a large C. His mother had taught him to read and write, but he couldn’t think what the initial could stand for.

Anna carefully broke the seal and unfolded the letter, pressing her lips together as her eyes traveled across the paper. Her face was tight, as if the muscles were straining to keep some private thought from spilling onto her face.

“Mother, why is the king sending you letters?” Matheus asked. “And how do you speak all those languages?” A prickle of dread formed in his stomach. “Are we in trouble?” he asked as terrifying images began to spill out from the dark places in his memory. Over the past year, news of unrest in other parts of the land had reached their village. Protestant dissenters were speaking out against the Catholic Church and Spanish rule. There were rumors that the king’s army had begun arresting people during rallies, or taking them away in the middle of the night.

Yet his family was Catholic, and he’d never heard either of his parents speak ill of the Crown.

Anna closed her eyes for a moment and then took a breath. “There’s something I have to tell you.”

The back door slammed, and Matheus jumped. His father, Joost, stormed into the room, leaving a trail of dirty boot prints in his wake. “What’s going on?” he boomed. “I saw a carriage leaving.”

“It was a message from the king.” Anna held up the letter. “He thinks it’s in danger.”

“What’s in danger?” Matheus asked. His heart sped up, sending a mixture of fear and frustration coursing through his body.

“Watch your tone,” his father snapped.

“It’s fine, Joost,” Anna said, clasping his arm. “It’s time to tell him.” She took a step forward toward her son. “There’s a special reason we sent you to be an altar boy, Matheus.” She shot a quick glance toward the window. “It’s about the altarpiece.”

Matheus had been waiting for his mother to say something that would shine a light on the fog that had settled over him since the messenger arrived, but her words only served to thicken the haze of confusion. Saint Bavo Cathedral was home to a magnificent altarpiece — a series of twenty-four paintings by the renowned Jan van Eyck. The work was heralded as a masterpiece — one of the world’s great treasures. Artists traveled great distances to study Van Eyck’s technique. What could the altarpiece possibly have to do with Matheus’s mother?

“My grandmother came from England specifically to protect the altarpiece. And ever since then, one of her descendants has watched over it.”

“Protect it from whom?” Matheus asked.

“There’s a dangerous group called the Vespers that’s been trying to steal the altarpiece for decades. And it’s up to our family — the Cahills — to keep it safe.”

It was as if she were still speaking one of those foreign languages for all the sense her words made to Matheus. “Why us? Wouldn’t the Church protect it?”

Anna shook her head. “They know nothing about the threat. The Vespers are masters at operating from the shadows.” She held up the letter. “The king’s Cahill advisers believe that the Vespers are behind the current rebellion, and are going to use it to seize the paintings. That’s why we need someone in the cathedral at all times.” She gave him a small smile and ruffled his hair. “Like an altar boy.”

Matheus took a step back. “But what am I supposed to do to protect it?” He’d never won so much as a wrestling match. How was he supposed to fend off a mysterious enemy?

Joost sighed and placed his hand on Anna’s shoulder, turning her away slightly. “I told you he was the wrong choice,” he murmured. “Send Lukas. He’s still young enough to be an altar boy.”

His words burned Matheus’s ears, and then spread to his chest like a growing flame. He knew his father was disappointed with him, but hearing proof was worse than he could have imagined, like waking up after a terrifying dream only to find the creature from your nightmare standing next to your bed.

“He’s the one,” his mother said firmly, returning to face Matheus. “The Vespers aren’t an invading army you can crush with superior strength. That’s what makes them so dangerous.”

“Lukas stands a better chance.”

“It’s my family’s responsibility, Joost. And we’ve chosen Matheus.”

Joost stared at her for a moment. “I hope you know what you’re doing,” he said, placing his cap on his head. “I must be off.” He nodded at Matheus. “Do your best, boy. We’re all counting on you.”

Anna watched him leave, and then walked over to fetch Matheus’s cloak from the peg by the back door. “Don’t listen to him,” she said as she draped the rough wool over his shoulders. “I know you’ll make me proud, Matheus.” She gave him a final kiss, opened the door, and ushered him out into the fading light.

“Come on!” Matheus half shouted, half groaned as he thumped his legs against Mungo’s sides. But the mule ignored his rider’s exasperated kicks and continued munching on the patch of clover he’d spotted off the road. It was the fourth snack break the beast had initiated in less than a mile. It wouldn’t even matter how Matheus was supposed to guard the altarpiece, if he never even made it back to Ghent.

The wind had picked up, and the skin on his neck and face began to sting. He reached down and stroked the coarse hair on the mule’s neck. “Please? If you get me back before dark, I’ll give you a carrot.” Mungo twitched his long ears, but kept chewing. “And a big, juicy apple.” The mule raised his head and snorted, spraying wet flecks of clover onto the toe of Matheus’s left boot.

Matheus sat perfectly still as the animal’s muscles twitched experimentally. It was crucial that Mungo feel it was his decision to continue. With a resigned whinny, the mule lumbered back onto the path.

Matheus sighed as he loosened the reins. Mungo was going to choose his own pace, anyway. As they turned down the road through the village, the mule broke into a surprisingly animated trot. His belly jiggled with each step, making it difficult for Matheus to keep his balance.

They rounded the bend, and Matheus’s stomach flipped. A group of boys about his age was standing in a circle, hooting and hollering as they watched a wrestling match. Matheus slouched deeper in the saddle and tugged the hood of his cloak around his face. But it was no use. They’d seen him.

Normally, the Protestant and Catholic children in the village got along, or at least left each other alone. But over the past few months, fights had been breaking out. Most of his neighbors knew Matheus was an altar boy, which made him a target.

“Look, it’s the choirboy!” a gangly lad shouted to his friends.

Matheus’s neighbor, Pietor, took a step forward. “Where’s your harp, angel?”

Matheus gave Mungo a firm squeeze with his calves, but the mule chose that moment to go investigate some apples rotting in the gutter. Matheus yanked on the reins with all his might, yet he couldn’t stop the mule from rushing headlong toward the fruit. He skidded to a stop on the slippery road, and Matheus tumbled off into a puddle of mud and decaying apples.

The boys roared with laughter. “Still think you’re something special, altar boy?” the tall boy called.

Matheus ignored them as he tried to remount, but his boots were covered with mud and his foot kept sliding out of the stirrup. After a few failed attempts, he grabbed the grimy reins and hauled Mungo away from the apples. He climbed onto a wooden crate and then swung his leg over the saddle. Matheus dug his heels into the mule’s bloated sides and urged him to walk forward.

The boys’ laughter echoed through the village square, but Matheus could barely hear them. All he could focus on was the man standing in front of the tavern, staring at him with a look of bitter disappointment.

Matheus tucked his chin into his tunic and stared at the ground as he rode by. He’d pretend he hadn’t seen his father. And his father could pretend he only had two sons.

Matheus couldn’t sleep. It was hard to trade the sleepy warmth of his snug house for the chill of the drafty dormitory. The wind always kept him awake like a restless bedfellow, tossing and turning in the night.

But the strange noises were the least of Matheus’s worries. His mother’s words echoed through his brain, drowning all other sounds. Matheus was in charge of protecting the altarpiece. But what did that mean? Was he supposed to pace back and forth in front of it all night, waving a club in the air? Matheus didn’t think the sexton would be too pleased with that option. And what would he do if someone did try to steal it? He couldn’t bear to recall the look he’d seen on his father’s face, and tried to shove the memory into the darkest corner of his mind. But he could still feel its sharp edge piercing through his thoughts.

The loud, even breathing of his fellow altar boys filled him with envy. They didn’t have mothers who gave them bizarre, impossible tasks. They didn’t have fathers who expected them to fail.

Matheus looked up at the narrow window across from his cot. A full moon wobbled in the corner, distorted by the thick glass. It was past midnight, which meant that the sanctuary would be empty.

It was time to check on the altarpiece.

Matheus rose and padded quietly toward the door, wincing as the cold from the floor seeped into his bare feet and crept up his legs. The long hallway was dark, but the moon provided just enough light for Matheus to find his way down to the first floor. He scurried across the courtyard and snuck in through the chapter house, where the bishop met with important visitors, and then darted past the cloisters into the front hall.

Matheus paused as he reached the entrance to the sanctuary. It was strange being there alone — normally, the cathedral was full of worshippers, priests, nuns, and altar boys. He took a step forward into the vast nave, the heart of the church. It looked even larger in the dark. The long center aisle seemed to stretch out interminably, and the pulpit at the end was hardly visible in the dim light.

Yet although Matheus generally hated the dark, there was something reassuring about the cathedral at night. During the day, the sun shone through the stained glass windows, filling the life-sized saints with a holy glow that made Matheus bow his head in reverence. But at night, the moonlight filtering through the panes made the figures look almost human.

As he walked down the aisle, passing the empty pews and dark alcoves that housed smaller altars and stone crypts, even the shadows were more comforting than menacing. The same shapes unfurled across the black-and-white floor every night like nocturnal flowers that lived for centuries. Time seemed to stand still in the cathedral. There was no changing of seasons. No cycles of birth and death. The air was always heavy with the smell of incense, the echo of music, and the memory of muttered prayers.

When he finally reached the pulpit, Matheus knelt and crossed himself before rising and turning to face the altarpiece. Even in the dim light, it took his breath away. The hinged panels were open, so the inner panels were visible — twelve paintings of different sizes that had been connected to form a screen. All together, the entire piece was larger than the front of his house.

Matheus’s eyes first traveled to the middle panel, where the figure of God was looking down from his golden throne. A shiver ran down his spine and he tilted his head to look at the large scene on the bottom panel, the most celebrated painting in the altarpiece — “The Adoration of the Mystic Lamb.” Van Eyck had portrayed the moment before the sacrifice. The lamb stood proudly on a pedestal in a green field, surrounded by angels. Groups of worshippers watched from a respectful distance. A sun shone down on the assembled crowd, and standing in the drafty, dark cathedral, Matheus could imagine the warmth on his skin.

Van Eyck had spent six years on the twenty-four individual paintings, and the detail was spectacular. Each of the hundreds of figures had a unique face and a distinct expression. The saints’ robes fell in lustrous folds onto the grass. Strange, exotic foliage bloomed in the background. Matheus could only imagine how far someone would have to travel in order to see plants like that. Although there was no proof that Van Eyck had left the Netherlands, there were rumors that his patron, the Duke of Burgundy, had sent the artist to faraway lands on court business. Could those journeys have anything to do with the Vespers?

Matheus squinted to examine something he had only found the other day. One of the figures in the bottom left panel had strange symbols embroidered onto his cap. They looked like letters, but they weren’t in a language Matheus had ever seen.

A loud thump shook the silence of the sanctuary. Matheus felt his heart flutter as he spun around. Could an attack be happening already? He spread his arms to the side, like a goose shielding a flock of goslings. Except that his spindly limbs would hardly stop a fly from landing on the altarpiece.

There was another thump, followed by the sound of metal hitting stone.

There was someone in the sanctuary.

“Who’s there?” Matheus croaked, cringing at how faint and wobbly his voice sounded in the vast cathedral. There wasn’t even an echo. He cleared his throat and tried again. “Reveal yourself!”

He looked around desperately for a weapon, but there was nothing. In a moment of panic, he darted behind one of the columns and hid there, shaking.

A flicker of light fluttered through the darkness. Matheus peeked out from behind the column and saw a figure holding a candle.

Do something! Matheus’s brain screamed at him, but his feet remained firmly planted on the ground.

“Hello?” a deep voice rang out. Instead of being absorbed by the mass of silence, it pushed off the walls like a great bird gliding from perch to perch.

Matheus stepped into the quivering pool of light cast by the candle, and exhaled when he saw that the figure was wearing the vestments of a priest. Although it was difficult to tell in the dark, Matheus was fairly sure he’d never seen the man before. “Good evening, Father,” he said respectfully.

“Hello,” the priest replied. It was unclear whether he was angry or just surprised to find an altar boy lurking in the sanctuary so late. “And who might you be?”

“My name is Matheus Jacobs.”

“Ah. I’m Father Gerard. I was just transferred from Bruges, you see. I suppose I’m still getting used to my new surroundings. It can be difficult falling asleep in a new home.” He waved his arm through the shadowy air. “Even one as magnificent as this.”

“I couldn’t sleep, either,” Matheus said, relieved that wandering through the chilly cathedral in the middle of the night seemed to be an acceptable cure for sleeplessness. “I had a dream that the altarpiece was in danger, so I came to check on it.”

The priest stared at him for a moment before chuckling. “I see. How very conscientious.” He took a step forward. “Although there is no cause for concern.”

“Of course, Father.”

“And it’s probably better for you to stay in the dormitory, Matheus. We can’t have small boys traipsing around at night, even well-intentioned ones.”

Matheus felt his cheeks flush. “Yes, Father.”

The priest smiled. “Good night, my son.”

Matheus scurried back up the aisle. When he reached the top, he paused and glanced over his shoulder. The priest remained facing the altarpiece. In the darkness, the outline of his robes blended with the shadows, making him look more like a statue than a man, as if he, too, were as much a part of the cathedral as the windows and the stone.

Matheus stepped into the sunlight and squinted, adjusting the heavy basket in his arms in an attempt to find a better grip. After breakfast that morning, Father Gerard had pulled Matheus aside with instructions for an errand. A family in a nearby village had just lost a child, and Father Gerard was sending them a basket of food.

Although Matheus had explained that only the older altar boys were allowed to go that far from the cathedral, the priest had insisted. He figured it would be good for Matheus — the journey would tire him out enough that he wouldn’t have any more trouble sleeping. He must have noticed the look of uncertainty on Matheus’s face, because he’d smiled and said, “You can take my horse, Brutus. He could use the exercise.”

As Matheus trudged down the narrow alley that led from the kitchen to the stables, he felt a mix of excitement and apprehension. He was happy to abandon his cleaning and polishing duties for the day, but it seemed wrong to leave the altarpiece unattended after yesterday’s strange events. Yet what harm could possibly befall it in the middle of the day?

Mungo was in the livestock pen, lying on the ground with his hairy legs in the air as he wriggled in the mud, trying to scratch a hard-to-reach spot on his back. When he saw Matheus, he rolled onto his side and clambered to his feet. He pricked his ears and stared at Matheus, a muddy, four-legged soldier at attention. “Sorry, Mungo,” he called. “Not today.”

The mule trotted over and stuck his neck through the fence to nuzzle Matheus’s sleeve. He gave Mungo a quick scratch on the nose and then pushed him away. “I’m not taking you. You’re too slow.” His destination was on the outskirts of the city, near his family’s village, and he wasn’t in the mood to spend another four hours begging the lazy animal to move.

He darted into the stable, where the high-ranking clergymen’s horses were kept, tacked up Brutus, a fine-boned bay, and led him into the yard. It was a little difficult to mount the tall horse holding a basket of food with one arm, especially once Brutus began whinnying and prancing in place. But Matheus eventually managed to hoist himself into the saddle.

Mungo snorted from his pen and stamped his hoof. “Everything’s fine,” Matheus said to the mule as he gathered up Brutus’s reins. “I’ll be back soon.” He gave Brutus a nudge with his heels, and the horse took off at a canter, scattering a flock of chickens into the air.

Matheus grinned as they flew down the narrow alley, splashing through the mud and swerving to avoid the maids emptying washbasins out of back windows. As they turned sharply out of the yard and onto the main road, Brutus lengthened into a gallop. It was exhilarating to feel the wind streaming over his face and to listen to the rapid thud of Brutus’s hooves as they swallowed the ground. If only his father could see him, thundering along the canal with his white altar boy robes streaming in the wind. Surely he looked worthy of protecting the altarpiece now.

By the time he reached his destination and delivered the basket, it was late afternoon, his favorite time of day. The landscape grew more confident in its beauty; the green of the hills stopped straining to upstage the blue sky, and the colors became softer, more harmonious.

Matheus shortened his reins and asked Brutus for a trot. If he hurried, he’d have time to visit the market outside of his village. Although Matheus had no money of his own to spend, it was fun to examine the wide array of goods — the mounds of red apples, the heaps of fresh fish, and silk all the way from the East.

Yet as he rounded the bend that led to the market, it wasn’t the sound of bargaining or the smell of roasting meat that caught Matheus’s attention.

A man was standing on a pile of wooden crates, surrounded by a crowd. He was giving some sort of speech, although it was difficult to make out the words. After nearly everything he said, the audience responded with cheers or shouts of their own.

“Will we allow the king to persecute our brothers?”

A number of people shook their heads while murmurs of disapproval rippled through the assembly.

“Are we going to sit idly by while the Church festers with the corruption of human greed?”

“No!” a few people replied.

Matheus brought Brutus to an abrupt halt, though his heart continued to beat rapidly. He knew he should turn around and take another route back to Ghent. In his altar boy robes, he was the last person the crowd would be happy to see. Yet there was something magnetic about the speaker. It was scary, but also a little exciting to see regular people — farmers, laborers, and merchants — talk about religion with such passion.

“Just last week, our brave brothers and sisters in Antwerp took it upon themselves to stand up for righteousness. They stormed the cathedral!” The audience cheered. “They burned the heretical art.”

Matheus’s stomach twisted as a wave of applause and cheers surged through the square. The mood of the gathering was shifting quickly.

A man standing in front of Matheus cleared his throat. He was tall, and wore a black hat and a black traveling cloak. “The cathedral in Ghent has even more treasures!” he shouted, his voice soaring over the crowd. “If we want to prove our might, we should destroy them as well.”

A look of concern flashed across the speaker’s face. “Well, perhaps it would be best to wait —”

“We cannot afford to wait. We’ve been suffering at their hands for too long.” The man in the cloak raised his chin. He was so tall that he didn’t need to stand on anything to be seen by most of the audience. “Now is the time to stand together, to show them our power.”

“Hear, hear!” a man called from the other side of the square, sparking a flurry of nods and murmurs.

“We will show them what we think of their idols,” the man in the cloak spat. “We’ll burn the symbols of their greed. All the paintings. Their beloved altarpiece.”

Matheus gasped, but the sound was lost in the frenzy of cheers.

“Friends, please,” the original speaker said. “I urge you to —”

The man in the cloak cut him off. “And we will destroy anyone who stands in our way!”

“We’ll start here!” a woman Matheus vaguely recognized shouted. “The Catholics in our village need to be taught a lesson!”

The audience began to stream onto the road, but the cloaked man remained in place, surveying the scene with a serene smile. As the square emptied, he walked toward the other side and disappeared into the shadows. But Matheus didn’t have time to worry about where he might be going.

Something terrible was about to happen. The mob was already moving toward Ghent — on a path that would take them straight through his village.

Matheus tugged on the reins and sent Brutus forward.

He wasn’t sure which was in graver danger: the altarpiece —

Or his family.

Matheus and Brutus tore through the woods, scrambling down slippery hills and through thick brush. But as they rounded the bend that led to the village, Brutus skidded to an abrupt stop. Matheus winced as he landed on the horse’s neck before righting himself with a groan. “Come on,” he said, gritting his teeth as he tried to kick Brutus forward.

But the horse just raised his elegant brown head and snorted, flicking his ears nervously.

That’s when Matheus smelled the smoke.

He shortened the reins and gave Brutus a firm squeeze, sending the horse into a stiff-legged walk. They turned the corner and Matheus inhaled sharply.

A different mass of people had already gathered in front of a small house. The roof was on fire. But instead of fetching water or trying to stamp it out, the crowd was shouting.

“Burn the infidels!” someone yelled, prompting a chorus of cheers.

The attacks had begun.

With a surge of dread, Matheus nudged Brutus into a canter, steering him off the road to pass the crowd of people. He continued around a bend, and when he was sure the path was clear, urged the horse into a gallop.

It’ll be all right, he told himself, as they tore along the tree-lined path that led to his house. It’ll be all right. He repeated these words in time to the rhythm of Brutus’s pounding hooves. It’ll be all right. He’d be able to warn his family before the mob arrived. They were on foot. He was on horseback.

He thought about the woman he’d seen in front of the burning house. The look of horror and heartbreak on her face as she saw her home destroyed.

That’s not going to happen to us.

They galloped up the hill that led to the village. The sun was low on the horizon, and he could see the glow of lanterns floating in the twilit haze.

Yet as Brutus tore up the hill, sending chunks of dirt flying in all directions, the lights grew brighter. They weren’t lanterns.

They were torches.

The mob must have cut through the wheat fields.

He was too late.

As Matheus steered Brutus toward his house, everything fell oddly silent. He couldn’t hear the crackle of the torches, or any shouts that might have been ringing out in the distance. All he could hear was the thud of Brutus’s hooves and the beat of his own heart.

There were already people outside. They were blocking the windows, so Matheus couldn’t tell whether anyone was still in the house.

The door opened, and Matheus’s father stepped outside. “What do you want?” Joost barked. Yet despite his harsh tone, there was fear in his eyes.

“We want you to stop defiling our city with your sinful ways,” a man said, prompting a round of cheers.

While the crowd shouted, a group of figures crept along the side of the house, toward the back entrance.

Matheus was about to follow them when a loud crack commanded his attention.

Joost ducked as a large rock came hurtling toward him, bouncing off the doorframe and landing on the ground with a heavy thud.

There was a flurry of movement as the mob scoured the path for more stones.

Right in front of Matheus, a large man with huge muscles straining against his tunic raised his arms and hoisted a melon-sized rock above his head.

“No!” Matheus shouted, jabbing Brutus with his heels. But the horse balked, unwilling to go anywhere near the loud mob with their flickering torches. He snorted and spun around on his back hooves.

Without thinking, Matheus launched out of the saddle and wrapped his arm around the man’s beefy neck. He released the stone as he thrashed around, trying to shake the boy off. Matheus kneed him in the stomach, and then dropped to the ground as the man hunched forward, clasping his belly.

He dashed through the crowd, pulling his father through the door before the mob had a chance to react.

“Matheus?” Joost said, as if he couldn’t quite believe that the boy standing in front of him was his son.

“Where’s Mother?” Matheus asked, frantically scanning the main room.

“Oh, beertje,” she said, rushing from the bedroom carrying Greet. “What are you doing here?”

Matheus ran to her, throwing his arm around her waist. “Are the windows locked? They might try to come in through the back.”

“Yes,” Anna said, placing Greet in her cradle. “We had a feeling this might happen. That’s why it was so important for you to guard the altarpiece.” Matheus’s chest tightened as he heard the panic and frustration in her voice.

“The priest sent me on an errand. I saw the mob form.” He took a breath, but all the words he was desperate to say seemed to be stuck in his throat.

“Which priest?”

“A new one . . . Father Gerard.” As soon as the name left his lips, a wave of cold passed over him. How could he have been so foolish? Father Gerard hadn’t just been taking a walk last night. He hadn’t sent Matheus away to be nice. He’d been trying to keep him away from the altarpiece.

He was a Vesper.

“I’m so sorry,” Matheus said hoarsely. “I didn’t know . . . I never should have . . .”

“It’s fine,” Anna said, placing her arm around him. “As soon as it’s safe, you’ll head back. It’s not too late.”

“No,” Matheus cried. The energy that had fueled his high-speed journey was gone. Now all he felt was weak and empty. “I’m not leaving.”

Joost walked over and placed his hand on Matheus’s shoulder. “You’ve shown extraordinary bravery tonight. I need you to stay strong and listen to your mother.”

A few hours ago, hearing his father speak those words would’ve filled Matheus with joy, but now all he could think about was the torchlight shining through the windows. The shouts and stamps that seemed to be rocking the very foundation of the house.

The three of them leaped up as a loud smash filled the room. Matheus felt his stomach plummet into his toes as a figure appeared in the doorway to the bedroom, shaking shards of glass from his sleeves.

It was the man in the black cloak.

“Excuse the intrusion,” he said, stepping into the main room. He had a slight foreign accent that Matheus hadn’t noticed earlier. “I would’ve used the front door, but I didn’t want to interrupt the festivities.”

Anna inhaled sharply. “You’re one of them, aren’t you? A Vesper.” Her tone was equal parts fear and incredulity, as if she were addressing a creature that was only supposed to exist in legends.

Joost stepped forward. “What are you doing in our home?”

“I was planning on paying a little visit to Saint Bavo this evening. I heard the altarpiece is even more striking by candlelight. And then it came to my attention that you might be able to illuminate the paintings for me even further.” He smiled. “You see, I am no expert on art, and I would very much appreciate any assistance you could provide.”

“We don’t know anything,” Anna said firmly.

The man gave an exaggerated sigh. “I was afraid you were going to say that.” He reached into his cloak and produced a long dagger. Matheus winced, as if the image itself were enough to slice his eyes.

The man whistled, and two more people stepped in from the bedroom. A man and a woman, both dressed all in black. The woman was wearing breeches instead of a skirt, but her strange ensemble was over-shadowed by the cruel smile that played across her long, thin face.

“Tell me how the map works, and we’ll leave peacefully. I’ll even get the crowd to disperse.” The man’s gaze slid toward Greet’s cradle. “Otherwise, you’ll just make things difficult for yourselves.”

“I don’t know,” Anna said, unable to hide the desperation in her voice.

The man looked over his shoulder and cocked his head toward the cradle. His two accomplices strode toward Matheus and Joost, and before either of them had time to react, forced their hands behind their backs.

“Get off me!” Matheus shouted, twisting painfully as he attempted to kick the woman’s shin with his heel. But she held tight.

The man took a few steps forward and started to reach into Greet’s cradle.

“No!” Anna screamed in a voice that was not her own. It was hardly human, a noise that contained all the agony in the world. She lunged for the man, jabbing her elbow into his throat. He gagged as he grabbed her wrist, and plunged the blade into her chest.

She gasped but didn’t scream, and for a moment, Matheus was convinced he’d seen it wrong. It was a trick of light. The dagger hadn’t touched her. Everything was going to be fine.

But then Anna fell backward onto the floor, landing with a thud that Matheus felt in his chest.

His father sank to his knees and stared mutely, as if not wanting to desecrate his wife’s last cry with sounds of his own.

“Search the house,” the man said. The woman in the black breeches released Matheus’s arms.

He ran toward Anna, skidding on his knees as he bent down.

“Mother.” He ran his hand along her cheek, which was just as warm and rosy as it had always been. She must have just fainted. She was going to be fine.

His eyes traveled down her still body until they reached the handle of the dagger sticking out of her chest, surrounded by an expanding circle of crimson. He stared at it uncomprehendingly, like he did when he came across a word he didn’t understand in the Bible. His brain couldn’t process the image. It didn’t make sense. It couldn’t be real.

“Mother,” he said, gently shaking her shoulder. “It’s fine. They’re leaving.” He glanced around the room. They must have gone into the bedroom. “We’ll get you help now.”

“Go,” his father croaked, pushing himself onto his knees. “Go now. They’re heading for the altarpiece.”

Matheus grabbed Anna’s hand. “Get up, Mother. We need to leave.”

“Matheus,” his father said, his voice cracking. “You have to go!”

He released his mother’s hand and watched it fall limply to the floor. He sat back on his heels as he felt a tight numbness spread through his chest, as if his rib cage was trying to squeeze his heart to death.

She was gone.

“Matheus!” his father cried. “Please.” A sob broke through him. “It’s what she would have wanted.”

He rose shakily to his feet and looked at his father. Joost nodded.

Matheus turned to his mother one last time, although it was difficult to see her from behind the warm tears that had begun welling up in his eyes.

He wiped his face on the sleeve and headed toward the door.

Matheus slipped out the side window. The mob was still in front of the house, but they had spread out along the road. They seemed to be awaiting instructions from the man in the black cloak.

He looked around. Brutus was nowhere to be seen.

He was entirely alone.

Suddenly, Matheus’s boots felt so heavy he didn’t think he could take another step.

His mother was dead. The altarpiece was in jeopardy. And he was ten miles away, with no way of getting back to Ghent.

The world began to spin, and Matheus had to grab on to a fence for balance. He wanted to sit down. He wanted to go to sleep and wake up when this was all over — or never wake up at all.

He was about to close his eyes when a shape emerged from the darkness. A four-legged shape . . . with very large ears.

It was Mungo.

From the shards of wood embedded in his curly hair, it looked like he had broken through the fence of his pen at the cathedral. And from the mud that covered his stocky legs, it looked like he’d been in a hurry to get here. Matheus didn’t know if the mule had come to find him, or if he’d been looking for food, but he didn’t care. He flung his arms around Mungo’s neck as his tears spilled into his rough mane.

“Grab that boy!” a voice shouted. Matheus spun around. It was the woman in the breeches.

Holding on to the mane for balance, Matheus climbed onto the fence and leaped onto Mungo’s bare back. Before he even had time to squeeze the mule’s sides, Mungo took off.

“Stop him!” the woman bellowed.

There was a flury of stomps as a number of people began running after Matheus. He glanced over his shoulder and saw a few of the men jump onto horses of their own and begin tearing down the road after them.

Matheus crouched down over Mungo’s neck, urging him forward. The mule stretched out into his best approximation of a gallop. Matheus slipped from side to side with every beat, latching on with his legs for dear life.

Mungo’s top speed was no match for the horses pursuing them. Matheus could hear the hoofbeats growing closer, their rapid thud outpaced only by the frantic beat of his heart.

It was difficult to steer without a bridle, but guiding Mungo with his heels, Matheus was able to urge the mule off the main road and onto a trail that led through the woods. The canopy of leaves was so dense it blocked out the last of the fading light, making it seem like they were galloping into an abyss.

Matheus heard the horses behind them whinny in protest, but Mungo was undaunted, and charged on.

A flurry of shouts and cracking whips broke through the sounds of pounding hooves and panting horses.

They were getting closer.

Up ahead was a stone wall that ran along the canal. If he could figure out a way to get around it — and convince Mungo to go in the water — they’d be able to use it as a shortcut to Ghent.

The trees thinned out as they got closer to the edge. In the faint light, Matheus could see the wall grow larger. He turned his head, searching for a gap, but the wall stretched out as far as he could see.

If he wanted to get over it, they’d have to jump.

Matheus dug his heels deeper into Mungo’s sides. The wall looked like it was about four feet tall. Could mules even jump that high?

The horses behind him grew even closer. He could almost feel their hot breath on his neck.

A few strides from the wall, Matheus squeezed Mungo as hard as he could and lifted himself off the mule’s back. Without missing a beat, Mungo rocked onto his haunches and launched into the air, clearing the top of the wall by a few inches and landing in the water with a splash.

Matheus twisted around and saw the horses skid to a stop. One rider grabbed on to his mount’s neck at the last minute. The other catapulted over his horse’s head and tumbled down the muddy bank, landing with a groan.

Matheus gave Mungo a big pat and sent him forward, wading through the murky water. In the distance, the normally dark cityscape was dotted with clusters of light.

The mobs had stormed the city as well. It was only a matter of time before they attacked the cathedral.

He only hoped he wasn’t too late.

By the time Mungo and Matheus entered the stable yard, they were both sopping wet and shivering. Yet Matheus could barely feel the cold.

He wasn’t sure he’d be able to feel anything ever again.

Matheus dismounted and raced through the deserted courtyard. “They’re coming,” he yelled as he scrambled into the chapter house. “They’re coming!” Although he could feel the force of the words in his throat, they barely seemed to make a sound. It was like hearing someone else shout from very far away.

A few of the other altar boys came running. “What’s wrong?” Jan asked.

“Get the dean. Or the canon. Anyone,” he panted.

“Matheus,” Father Gerard said, stepping into the room. “Tell me what’s going on.”

“You!” Matheus found himself saying. “Get back.” The altar boys’ eyes widened, but he didn’t care. Let them think he’d gone mad. “I know what you are.”

“I assure you, whatever you think is wrong. Come with me.”

“No,” Matheus spat, sensation returning to his body like a frostbitten limb removed from the cold. Except that all he could feel was hot rage. “Your friends are coming for the altarpiece, but I won’t let them take it.”

Father Gerard’s face paled, but his expression remained calm. “Jan, run to the guard tower,” the priest ordered another boy. “Tell them to send as many soldiers as they can. And then wait there until morning. It won’t be safe to come back.”

Jan stared at him for a moment, as if unsure whether the priest was being serious.

“Now!”

He took off at a sprint.

“Thomas, go lock all the doors. And secure the windows in the offices and your dormitory.” Thomas didn’t wait to be told twice.

“Getting rid of the altar boys won’t help you,” Matheus said. “I’m not going anywhere.” He pushed past the priest into the corridor, and began running toward the sanctuary.

“Matheus!” Father Gerard shouted. He glanced over his shoulder and saw the priest sweeping toward him, his robes billowing behind him.

Matheus turned back around and sprinted down the center aisle. When he reached the altarpiece, he spun on his heel and stretched his arms out. “Stay back!” he shouted as Father Gerard reached for him.

“My son,” he panted. “You misunderstand. I am not your enemy.”

“Then what are you, Father? Are you even a real priest?”

The stern look on Father Gerard’s face snuffed out the flames of Matheus’s rage. “I am. I have committed my life to two purposes: serving God, and fighting those who seek to undo his work.”

“The Vespers?” Matheus whispered. The priest nodded. “They’re coming,” Matheus continued. “They’re coming for the altarpiece.”

Father Gerard pressed his lips together and turned to face the paintings.

“What do they want with it?” Matheus asked. “The man — the Vesper — said something about a map.”

The priest looked at Matheus, startled. “What do you know about that?”

Matheus felt his stomach lurch. “It was my mother, but she never had the chance . . . to explain.” Father Gerard stared at Matheus for a moment. His features folded into comprehension, and he placed his hand on Matheus’s shoulder. “I am so, so sorry, my child.”

They were interrupted by the sound of stomping boots. Father Gerard and Matheus spun around and saw a line of soldiers marching down the aisle. Seeing their swords glittering in the candlelight was almost as incomprehensible as seeing the dagger in Mother’s chest. Weapons did not belong in a church.

The captain stepped forward and removed his hat. “We’ve secured the entrances, Father,” he said, bowing his head. “And I have men surrounding the perimeter.”

Father Gerard nodded. “How long do you think we’ll be able to hold them off?”

The captain shifted uncomfortably. “There are smaller mobs all over the city. They’ve been burning shops, breaking windows. If they keep going as they are, we’ll be fine. But if they decide to band together . . .” He trailed off.

“If there’s any chance of them gaining entry, we’ll have to move the altarpiece,” Father Gerard said briskly, and the soldiers’ eyes widened.

“We can’t risk moving it out of the cathedral tonight, though,” Father Gerard continued. “We’ll have to dismantle the altarpiece and hide the paintings somewhere inside the building.”

“How about the crypt?” called one of the soldiers.

“They’ll look there.”

“The kitchens?”

The priest shook his head.

This is useless, Matheus thought. What was the point of hiding the paintings? The Vespers wouldn’t let the mob stop until they found them. They weren’t going to leave empty-handed. If all the soldiers were in the cathedral, it would be hard to convince anyone that the altarpiece had gone elsewhere. Unless . . .

“Father,” Matheus said, turning to the priest. “I have an idea.”

Matheus sat on the stone steps that led up to the now-barren altar. He shivered as the damp from the stone seeped into the breeches that had barely had time to dry since he and Mungo had emerged from the canal.

The sanctuary was completely empty, save for him and Father Gerard. They’d overseen the soldiers as they dismantled the altarpiece and carried the paintings to the chosen hiding place.

Over the past hour, the noise outside had increased. What began as a smattering of shouts had grown into a frenzy of angry chants, stomps, and shrieks that filled the cathedral like chords from a demonic organ.

The number of torches had multiplied as well. The faint flickers behind the stained glass windows grew into flames, engulfing the figures in a shadowy blaze that could only have escaped from the depths of hell.

The crackle of burning wood grew louder, and Matheus could now smell the smoke drifting through the gaps in the windows. There’d been a number of bangs against the door — probably from men trying to kick it in — but it had held.

But then there was another sound at the door. A louder thud followed by an ominous crack.

“They’ve found a battering ram,” Father Gerard said, rising from the step.

He turned to Matheus. “It’s time. Are you ready?”

Matheus nodded, even though his frantic heart was trying to convey a different answer.

He squeezed Matheus’s arm. “Good luck.”

Matheus sprinted up the aisle and tore up the spiral staircase that led to the bell tower. A few steps from the top, he turned around and took a deep breath, running over the plan in his head.

There was another crack, followed by a chorus of shouts that echoed through the sanctuary and up into the tower. Matheus’s whole body froze.

The clash of swords joined the cacophony of sounds that filled the cathedral. The soldiers must have started trying to drive the mob out. But it was clear they were outnumbered, because soon shouts were ringing from throughout the building.

“Check the crypt!” Matheus heard someone cry.

“They could’ve hidden it in the balcony.”

“Look inside the pews!”

Sweat formed on Matheus’s forehead as the noises grew louder. They were getting closer.

“Search the towers,” a low voice commanded, setting Matheus’s cheeks ablaze while his stomach churned.

It was the Vesper.

A ball of rage surged through him, incinerating every other feeling. His muscles were on fire. He felt like he could lift the altarpiece himself. He could fight off the intruders single-handedly.

He could slam the man into the cathedral wall until his body disintegrated into dust.

Matheus jumped down the steps onto the landing, his hands clenched into fists. But then another thought fluttered to the surface of his mind, like a phoenix rising out of the flames.

His job was to protect the altarpiece. His mother had given her life for it.

Matheus took a deep breath and returned to his spot on the step.

The shouts grew louder, punctuated by screams. Matheus closed his eyes, trying to focus on something other than the terrible scene playing out below. He thought about the main panel of the altarpiece. The green meadow sparkling in the dazzling sunlight. The snow-white lamb.

The sound of approaching footsteps echoed up the staircase.

That was his sign.

Matheus scrambled up the stairs, feeling the temperature change as he approached the top. He’d never been up here, as the bell tower was strictly off-limits. But now was not the time to worry about protocol.

He ducked under a low doorway, shivering as the night air swirled around him. The massive bells blocked almost all of the moon, but the sky was full of glittering stars. Matheus ducked under a wooden beam and took a few shaky steps along the narrow ledge. To his right was the chamber that housed the ropes and wheels that controlled the bell. To his left was a low stone wall, and beyond that, nothing. Anyone unfortunate enough to lose his balance would plummet nearly three hundred feet to the ground.

Against his better judgment, Matheus turned his head to look over the edge. Through the dizzying expanse of darkness, he could make out the flicker of flames on all sides. The cathedral was surrounded.

There was another burst of footsteps, followed by a series of shouts. At first, all he could see was a line of shadows gliding along the stone wall of the staircase. But then two figures careened around the bend, waving their torches through the dark air — the Vesper and another man in black.

Matheus scurried around to the other side of the bell, praying that the shadows cast by the rafters would obscure his own. He fished the bits of cloth Father Gerard had given him out of his pocket, stuffed them in his ears until the world fell silent. Then he stood on his toes and reached for the heavy rope that hung from a hook on one of the beams.

Their shadows began sliding along the ledge. If they looked down into the bell chamber, they’d find what they were looking for. At Matheus’s suggestion, the guards had dismantled the altarpiece and hidden the panels along the inside of the bell tower.

He unhooked the rope and held it tightly with both hands as he watched the men creep closer.

It was time.

Matheus took a deep breath, bent his knees, and pulled on the rope as hard as he could. There was a low clank, and suddenly, Matheus was yanked off his feet. He screamed and held on to the rope as he felt himself twisting in the air. Then another sound exploded through the tower as the bell began to ring. Matheus shut his eyes as the vibrations coursed through him, shaking every bone in his body. In the brief moment of reprieve, Matheus thought he could hear the Vespers screaming, but he wasn’t sure.

The bell tolled again, and then again, sending new waves of sound pulsing through him. For a few moments, all that existed was the peal of the bell, as if the sky had opened up and God himself was shouting vengeance from the heavens.

Matheus opened his eyes and saw the men stumbling toward the door, their faces contorted in agony.

Soon, the twisting stopped, and he lowered himself back onto the ledge. His feet gave out and he fell onto the cold stone in a crumpled heap. He began to cry noiselessly. The ringing of the bell had silenced all other sounds in the world.

Early the next morning, Matheus stood at the top of the bell tower, helping Father Gerard oversee the removal of the altarpiece. The mob had finally dispersed, and the mayor of Ghent had agreed to let them keep the altarpiece in the fort until the city settled down.

After the last panel was safely removed, Matheus turned to watch the sun rising over the eastern edge of the city, casting a shimmering glow on the houses and flecking the river with sparks of gold light. It was hard to believe that only a few hours earlier, the torch flames had ripped open the night sky.

As he scanned the horizon, he tried to imagine the scene at his house. Was his mother still lying where she fell? Was the house even standing? Or had it been devoured by the hungry fire he’d seen spitting and hissing on the torches? He prayed that his father and baby Greet had emerged unscathed.

“You were very brave last night, Matheus,” the priest said, placing his hand on the boy’s shoulder.

“Thank you, Father.” He supposed he should be proud, but all he felt was loss. The altarpiece was safe, but his mother was gone.

Father Gerard turned to look at him. “You may not understand it now, but you’ve done the world an enormous service. The Vespers are a dangerous force. If they had gotten hold of the altarpiece, they could have become even more powerful.”

“Because of the map? What was that man even talking about? There’s no map in any of the paintings.”

“The Vespers believe that there are hidden symbols in the altarpiece that, when translated correctly, identify a number of secret locations around the world. Hiding places for something of great value.”

Matheus tilted his head to the side. “A treasure?”

Father Gerard gave him a sad smile. “If only that were it.”

Matheus closed his eyes as the terrible image he’d been struggling to banish took root in his mind. His mother lying on the floor. Whatever the Vespers were looking for, they couldn’t be allowed to find it. Matheus would see to that.

A soft wind blew through the tower, and the air streaming across the bell created a whistling sound, like ghosts of last night’s ringing. No, Matheus thought as he listened closer. It sounds like a voice. He could almost hear the bell whispering to him. He craned his head up to look at the brightening sky, and mouthed a silent good-bye.