OLIVE KNEW THAT she was running—she could hear her feet hitting the painted grass, and the smoky air around her had become a grayish blur—but the rest of her mind had switched off. Her body had taken over, flying her toward the back of the stone house.

Behind her, Horatio’s commanding voice rose above the fire. “You two, split up and evacuate the Deweys and as many other neighbors as you can find. Run!”

Olive’s heart was a hot stone at the base of her throat. Choking for air, she leaped up the back steps and through the painted door.

The roar of fire grew louder as she tore from the empty kitchen into the hallway. With each step, she pushed deeper into the crackling steam. Her eyes stung. Her lungs burned. She lurched forward until she reached the spot where the front of the house should have been.

All that remained of the entrance was a wall of strangely colored flames. The painted stones were trying to re-form themselves, but the heat was too fast and strong. Green streaks exploded from the bubbling paint, sweeping inward. The wooden floor had begun to boil.

Mr. and Mrs. Dunwoody were still scribbling away as Olive raced through the library doors.

“Dad!” Olive grabbed him by the sleeve. There was something strange about its fabric; something slick and slippery. “Mom! We have to get out of here! The house is on fire!”

Mr. Dunwoody looked up at the library’s farthest wall. The glimmering books were puffing into flame one by one, like fiery kernels of popcorn. The haze in his eyes seemed to thin.

“You appear to be correct, Olive.” He pushed back the desk chair. “Funny—I didn’t hear the smoke detectors.”

“That is funny,” said Mrs. Dunwoody, whose eyes were also looking clearer. “Especially as I recall you changing the batteries when we moved in, which leaves us well within the recommended twelve-month usage limit. Perhaps we should—”

“We can check batteries later,” said Olive, hustling both parents toward the double doors. “Let’s go.”

“Is there any chance that the batteries themselves weren’t new?” asked Mr. Dunwoody as they hurried along the hallway. The rug burst into flames behind them.

“I doubt it, dear, as we’ve only owned this house for six months, and I don’t believe we packed old batteries in order to bring them here with us,” Mrs. Dunwoody answered.

“Ah, yes,” said Mr. Dunwoody. Blue-green fire snaked along a brushstroke in the plaster just to his left, opening the wall like a zipper. “A logical point, darling.”

Olive managed to get both of her parents through the back door just before a gust of flame ripped down the hallway, tearing open the painted ceiling. Jets of blue fire rippled along the edges of the rooftops.

A huge orange cat met them in the yard. “There you are!” he cried. “Let’s get your parents out of here quickly!”

“Shh!” Olive hissed. “They’ll hear you!”

“Yes,” said Horatio shortly. “Well, they are going to have to climb through a picture frame while holding my tail in a moment. We’ve got larger concerns ahead.” With a sharp look at the Dunwoodys, Horatio bounded ahead of them down the misty hill.

Olive ran after him, dragging her parents by their smooth, slippery hands.

They all tumbled through the frame into the unlit hallway. Leopold and Harvey waited on the carpet. Walter, Rutherford, and Mrs. Dewey stood beside them, their milky eyes now clear and intent. Huddled in the shadows several steps away were Mr. Fitzroy, the old woman with the nightcap, and several other neighbors in nightclothes.

But Olive wasn’t paying attention—not to the people around her, not even to the burning sensation in her own fingers and feet. She was watching her parents.

The moment they were through the frame, Mr. and Mrs. Dunwoody had crumpled to the floor. Their eyes were closed, and their teeth were gritted. Mrs. Dunwoody let out a muffled scream. Olive had never seen her parents in such pain—not even two years ago, when Mr. Dunwoody had been so preoccupied by an algorithm that he’d walked straight into the coffee table and broken two toes. She knew what they were feeling. She’d felt it herself when she’d stayed Elsewhere too long and her body had begun to turn to paint. It was like having your skin skewered by a swarm of icy needles. And the longer you’d stayed, the deeper the needles went.

She dropped to her knees next to her mother. “Are they going to be all right?” she asked, her voice wobbling.

Mrs. Dewey knelt down beside her. “That they feel pain means they’re still able to feel,” she said firmly, before pressing her head to each of the Dunwoodys’ chests. Olive noticed that Mrs. Dewey kept clenching her own shiny hands. Nearby, Walter was chafing his arms, and Rutherford was jiggling anxiously from foot to foot—but with Rutherford, this could have meant almost anything.

“I hear heartbeats,” said Mrs. Dewey, straightening up at last. “It’s not going to be pleasant, but they’re alive, and they’ll stay that way. Help me move them into Olive’s room,” she told Walter and Rutherford. “We’ll make them as comfortable as we can.”

Starting with a moaning Mr. Dunwoody, Rutherford, Walter, and Mrs. Dewey struggled off through the nearest bedroom door.

Olive glanced around the chilly hallway. “Where are Morton and his parents?” she asked, squinting into the shadows.

“We could not find zem, milady,” Harvey spoke up. “We searched zair house, and we called to zem—but zey did not emerge. We could not delay saving zee othairs.”

Olive turned toward the painting of Linden Street. Even without the spectacles, she could see the fire rippling within the canvas. It wasn’t just in the distance anymore. It was surging outward, its reaching green-gold limbs grasping each house, climbing each painted tree.

From the corner of her eye, Olive caught another flicker. In the painting of the bowl of strange fruit, a tongue of fire was licking at the table. A crackling grass fire was sweeping toward the trees in the painting of the moonlit forest. Down the staircase, the first hints of smoke were coming from the silvery lake.

“Oh, no,” she whispered to the cats. “It’s spreading.”

“Elsewhere has many pieces, but they are all connected,” said Horatio quickly. “Aldous could move between them. Magic can move between them.”

“So what do we do?” Olive watched a ribbon of flame climb a painted tree. “How do we stop it?”

The cats exchanged a look.

“It’s too late to stop it, miss,” said Leopold. “Even if it were an ordinary fire. Which it isn’t.”

Olive grabbed a hank of her own hair and pulled. “Maybe Walter or Mrs. Dewey could—”

“Zat would be like a duel between a broadsword and a begonia,” said Harvey.

Olive whirled back toward the burning painting of Linden Street. There might still be time to find Morton and his parents, if they were lucky. But what about the three stonemasons and Baltus in the kitchen downstairs? What about the friendly orchestra, and the castle porter, and Roberto the Magnificent, and the dancing girls, and the Parisian pigeons? What about everybody else?

She spun toward the cats. “We need to get everyone out. Everyone.”

Horatio’s eyes widened. “And then what? We can’t simply let them roam free; they won’t be safe!”

“They won’t be safe in burning paintings either,” Olive pointed out. “They need us.” She crouched down in front of the cats. “All this time, you’ve protected this house. Now you can protect the people in it instead.”

The change in Horatio’s face was tiny, but Olive knew him well enough to see it. She turned to the others. “Leopold, Harvey: Go and get everyone out of Elsewhere. People. Animals. Everyone.”

Leopold straightened to his fullest height. “Aye, aye, miss!”

“Oui, milady!” Harvey added.

With a salute and a bow, the two of them flew off into the darkness.

Olive met Horatio’s eyes. “Let’s find Morton.”

Back inside the painting of Linden Street, the cool, misty air had turned hot. The oily stench of burning paint hung in the air. Olive and Horatio tore up the hillside, avoiding the ripples of fire that flowed down it, leaving only greasy ash behind.

They raced along the deserted street. The fire had nearly finished with the old stone house. A sooty smudge marked the spot where Aldous and Aurelia had stood. The rest of the house was a heap of smoldering, sizzling black. The fire had moved onward, climbing from one treetop to another, swallowing the next houses in the row. Mrs. Dewey’s house was in flames. And the Nivenses’ tall gray house was a tower of writhing light.

“Morton!” Olive yelled. “Morton!”

There was no answer but the roar of fire.

Horatio streaked ahead. “I’ll check inside!”

“Horatio, no!” Olive panted after him. “It’s too dangerous!”

“Go to the backyard,” the cat shouted over his shoulder. “I’ll look for another way out!” With a bound, he disappeared through a hole in the flames.

Olive trampled a patch of grass that was still struggling to repair itself and skidded to a stop in the backyard. She stared up at the tall gray house. One small portion of the upper story was not yet on fire. Below the still-solid rooftop, an open window exhaled streams of smoke. The wall below the window was a mass of flames.

“Horatio!” she shouted, between coughs. “There’s an open window back here!”

There was no answer, whether Horatio heard her or not.

Olive looked desperately around. As she surveyed the scorched yard, she noticed something she hadn’t spotted before.

The fire wasn’t just eating the objects in this painted world. It was eating everything behind them: air, earth, canvas. What was left after even the paint and ash were gone was nothing—just blackness, like a hole without any bottom.

A gap was opening in the earth before the old stone house, where the fire had begun. As Olive stared, the gap widened into a trench large enough to swallow a person whole. And as for what would happen if a person fell through that trench—

“Olive!” shouted a voice.

Olive glanced up at the burning house. A round, pale face had appeared in the only remaining window.

“Morton!” she shouted. “Is Horatio with you?”

“Yes!” Morton shouted back. “And Mama and Papa too!”

“Then jump! You can make it!”

Morton shook his head wildly. “Mama won’t leave!”

“Mrs. Nivens!” Olive shouted, raising her voice even higher. “If you hurt anything, it will fix itself!”

“No,” Morton yelled. “She doesn’t want to leave!”

Fresh streaks of fire rose toward the window like the fingers of a groping hand. The air thickened with the stench of smoke. Olive coughed, each breath scraping her throat like steel wool.

“You’re going to have to throw her,” Horatio’s voice commanded from inside the window. A flash of orange fur appeared in the opening. “Harold, Morton: Pick her up.”

Mary’s struggling form appeared on the sill. Her sweet, pretty face was twisted with fear. “No!” Olive heard her shout. “There’s nothing out there for us! We belong here!”

“Ready?” Harold’s voice boomed. “One . . . two . . . three!”

With a shriek, Mary flew through the window and plunged to the lawn below.

“Sorry, Mama!” Morton called after her.

Morton leaped next, his nightshirt billowing, and landed with an almost-proud bounce on the grass. Harold dove after him. The moment he crossed the sill, a gust of flames poured through it, nearly catching the tail of his jacket. The wall crackled. The painted glass dissolved in a burst of smoke. The flames slithered upward, groping for the rooftop.

Horatio halted on the sill. His eyes flicked from the house’s interior to the disappearing lawn below. “Get them away!” he shouted down to Olive. “I’ll be right behind you!”

The roof tore open with a fountain of blue flame. The upper floor sagged. Olive heard Mary’s and Harold’s gasps, slashed by the pitch of her own shriek.

“Run!” she screamed, shoving Morton and his parents ahead of her.

They raced down the smoking hillside, leaping over the widening chasms.

In the scorched lawn where the stone house had stood, Olive spotted one small, terrified spider scuttling over the grass. She swept it up into her palm before running on.

At the picture frame, Olive stopped. She glanced over her shoulder, looking for a flash of orange fur, but all she could see was a row of fiery coals where Linden Street’s grand houses had stood.

She banged at the surface of the painting. Her hands stung so badly that she gasped. When she glanced down at her palms, she saw that the skin was perfectly smooth—too smooth. Her feet were numb. Of course they were, Olive realized. She had been inside Elsewhere much too long. Even with Aldous gone, some wisps of its power clearly remained.

Her body flared with panic. Her breaths came faster, each one dragging in a prickly swirl of smoke. She banged at the surface again.

Out in the dim hallway, one of the painted neighbors looked up. She turned to another person, speaking quickly. Olive watched the message travel along the hall until suddenly a black cat leaped into the frame.

“Leopold,” Olive choked, “please take the Nivenses out.” She set the frightened spider on his back. “And this spider too.”

“What about you, miss?”

“I—” Olive stopped, coughing. “I’ll wait for Horatio.”

Leopold nodded once. “Be careful, miss.”

Olive watched Leopold, then Morton, then Harold, and finally reluctant Mary disappear safely through the frame. Then she turned back toward what remained of Linden Street.

As Olive ran up the hill a final time, the air was growing hot and thin. Smoke coated her mouth and throat. The ground beneath her felt brittle; her feet crackled in the burned brushstrokes, sending flakes of oily ash into the air.

Cracks had appeared all around, leading down to nothingness. Olive leaped over them, skirting the huge, scorched hole that had emerged in the McMartin yard, racing with a new burst of panic toward what remained of the Nivens house. Her numb legs just managed to keep her upright.

The tall gray house was only a black heap. A few embers still glowed in its foundations. The walls had collapsed into ashy lumps, where wisps of paint undulated gently in the rising air.

“Horatio?” Olive called, running toward the back.

The window where she’d glimpsed the orange cat had dissolved into the smoking rubble. Burned paint bubbled where the back door had been. Another black crevasse was widening across the yard.

“Horatio!” Olive called again.

A cloud of smoke rushed into her open mouth. She doubled over, coughing, inching closer to the embers. Her legs and arms could barely feel the heat. Her fingers might as well have been made of plastic. Olive wondered if a spark from the fire would incinerate her as quickly as Lucinda and Annabelle, making her vanish in one sudden, blazing streak.

But she wasn’t going to turn away. Horatio was here somewhere. She couldn’t abandon him, frightened or trapped or hurt, or wondering why she had never come back.

She crept into the sizzling remains of the house. Her eyes fogged and watered. Itchy sweat dribbled down her collar. Her lungs gave an angry throb as she inched forward into the heat’s core.

Something that had been a wall fizzled away as Olive moved closer. Through the smoke, she could see another bottomless hole where the staircase had stood, and a black smudge that had once been the hallway floor . . . and, half buried in a pile of ash, its rich orange color dimmed to gray, one long, thick, motionless tail.

Horatio.

Olive plunged forward.

The painted ground snapped under her weight. She leaped as the floor crumbled beneath her, landing beside the big orange cat. The smoke was thick, and the stifling air was warped with heat, but she could see that the cat didn’t move.

He didn’t open a bright green eye, or twitch a whisker, or stir one single strand of fur as Olive dragged his limp body out of the ash and into her arms.