The summons arrived later that day.

Hailstorm’s messenger found Winter on one of the tallest spires, gloomily picking apart the seal he’d caught. He hadn’t been able to find anywhere else to eat in peace; everywhere he went, dragons bowed or hurried over to offer him things or buzzed around with a million questions.

And as the day wore on, he’d heard the whispered phrase more and more.

The Diamond Trial … the Diamond Trial …

Every dragon over the age of three knew what it was, but no one could give him any details. The Trial was shrouded in mystery, and there was no one left in the palace who’d survived it, since it hadn’t been used in so long.

“Prince Winter,” said a clipped voice behind him, shaking Winter out of his thoughts. The messenger handed over a small slab of ice marked with precisely carved letters. She stepped back and bowed deeply. “Good luck, sir.”

According to the brief, impersonal message, the Trial was scheduled for sunset the next day.

What would happen if I did something terrible between now and then? Winter wondered. If I snubbed the wrong dragon, or dripped seal blood in the pristine courtyard, or broke one of the queen’s ice sculptures? Would I drop down the ranks? Would someone else have to face the Trial with Hailstorm?

He had a feeling nothing like that would work. The plan was in motion. And Narwhal wouldn’t put Snowfall into the Trial, no matter what Winter did. Queen Glacier would be too furious if she came back and found her daughter’s life in jeopardy.

And if he fled or tried to refuse the challenge, he’d bring shame upon his whole family, and cost Hailstorm any chance he had at climbing the rankings before his hatching day.

For a moment Winter turned the message slab over in his talons, and then he spread his wings. The only thing he could do was fight. Fight for his new position at the top of the rankings. Fight for his family’s melting honor.

Fight for his own life.

It was what Hailstorm and his parents would want him to do, even if they hoped he would lose in the end. He still had to go down like an IceWing warrior.

He spent the rest of the day in the palace library, looking for the Diamond Caves mentioned in the summons. He’d never heard of them, but there they were on an old map. If the Ice Kingdom’s peninsula was shaped like a dragon’s head, the caves were located where her frostbreath would come out.

Diamond Caves. The most famous Diamond in IceWing history was Queen Diamond, the mother of Prince Arctic, the animus who had been stolen by Foeslayer and the NightWings. As a young dragon, Queen Diamond had given the tribe the gift of healing — five narwhal horns enchanted to cure frostbreath injuries in case any IceWing ever wounded another. But there had been a few other Diamonds over the years as well. He wondered if the caves and the Trial were named after one of the historic Diamonds, and why.

He slept poorly that night, troubled by dreams of Moon and Qibli and Hailstorm all in danger, their scales melting and shifting into other colors as he searched for them in the halls of the ice palace. Every time he woke, he wondered why he hadn’t been visited by Scarlet again. He could only imagine her wrath when she discovered that Pyrite/Hailstorm was gone.

The next morning he found Lynx and asked her to train with him. The familiar fighting patterns came naturally, and focusing on her attacks helped drive out all the other worries in his head. They leaped and wrestled in the snow outside the palace until they were exhausted.

Afterward, as they washed each other’s dark blue blood off their claws and scales, they heard wingbeats and looked up.

Queen Glacier was back. Behind her flew two generals and Icicle.

Winter watched them soar into the palace. He wondered what the queen would think of Narwhal’s scheme. Would she stop it? Would she rearrange the rankings before sunset? Could she do that, even with the summons already issued?

If she could, she didn’t. A few hours later, she was among the twelve dragons assembling in the courtyard to fly to the Diamond Caves.

“Prince Winter,” she said, and he bowed as deeply as he could. The IceWing queen was huge and majestic, far more beautiful and imposing than any other queen in Pyrrhia. He wondered if he was only imagining that he could see sympathy in her eyes.

“You’ve served the tribe well, returning Prince Hailstorm to us,” she said. “I wish you luck in the Trial.”

“Thank you, Your Majesty,” he said. There was an uncomfortable prickle at the back of his neck that he suspected meant Hailstorm was nearby, staring at him.

“You will fly alongside me on the way to the caves,” she said. “I wish to hear about everything that has happened since you left us for Jade Mountain. I’ve heard your sister’s version of events, but I suspect another perspective would be instructive.”

“Yes, Your Majesty,” he said. “May I ask what’s going to happen to Icicle?”

She looked grave. “It’s a good question. Queen Glory is … not like other queens. I thought she would demand Icicle’s execution, but instead she said she would leave Icicle’s punishment entirely to me in exchange for something unusual: a cutting from our moon globe tree.”

“What does that mean?” Winter asked.

“I wasn’t sure either,” said the queen. “Apparently with plants, you can take a piece of it and bury that somewhere else, and then a new plant will grow from that piece. The idea, I think, is that she wants to grow moon globe trees in her rainforest, to bring the gift of light to the RainWings and NightWings.”

“Oh,” Winter said, startled. He didn’t know quite how to wrap his head around this. “Will it work?”

“It might,” said Queen Glacier. “The tree is enchanted to behave like a real tree. And I can see how such a thing would benefit her tribes greatly, although, as I said, it’s an unusual queen who would choose a path toward peace and cooperation over clear and simple vengeance.” She flicked her wings, frowning thoughtfully. “The question is whether her tribes will be satisfied with this solution. I suppose we’ll see. It may partly depend on how I ultimately punish Icicle, but I haven’t decided that yet.”

They lifted off into a cloudy gray sky, flying southwest with Tundra and Narwhal in the lead and Hailstorm trailing at the back, as befitted his last-place ranking. Winter had to struggle to keep up with Queen Glacier’s pace, but she didn’t seem to notice.

And since he had a feeling he was about to die, he told her almost everything — about Icicle trying to kill Starflight and how Winter stopped her; about the rainforest and the volcano; about going in search of Scarlet, meeting Pyrite, and encountering the mysterious NightWing in the valley.

He left out a few things, though. Moon’s powers and her prophecy. The fact that his friends were waiting for him in Possibility at that very moment. The way he felt about them, especially Moon.

The queen only stopped him once during his story. “Who?” she asked.

He paused, startled. “Your Majesty?”

“You said there was an IceWing with the Talons of Peace.” Queen Glacier shot a glance at the hole in the clouds where a piece of sunlight had muscled through. “Who was it?”

“His name was Cirrus,” Winter answered. “I didn’t know him and he didn’t know me. He was … confusing.”

“We haven’t had a Cirrus in many years,” the queen mused. “And I don’t recall any IceWings leaving us for the Talons of Peace — unless they were from the lower classes, outside the rankings. Perhaps that’s why I don’t know him. Or perhaps he changed his name.”

“He acted like an aristocrat,” Winter said. It hadn’t even occurred to him that Cirrus might be from the outskirts of the Ice Kingdom. That would explain why he didn’t tell Winter his ranking, though. “He implied that he knew my parents, but in a way that seemed like he was lying.”

“Hmm,” Queen Glacier said. “I’ll look into it. Go on.”

Most of the clouds had cleared and the sky was shading into a brilliant orange-red when they finally dove out of the sky toward a snow-covered evergreen forest clustered at the base of an enormous white cliff.

Pine needles jabbed Winter’s snout as he dropped through the trees to the forest floor. The scent of the pines surrounded them and the snow crunched like crushed paper under their talons. He thought of the Pyrite scroll spell, now carefully tucked away in the skyfire pouch around his ankle.

A cave mouth yawned in the side of the cliff, glittering with stalactites as sharp as teeth. Ice covered the walls, floor, and ceiling all the way into the tunnel, as far as Winter could see before darkness took over. He touched the moon globe over his shoulder, making sure it was there and still working.

“Princes Winter and Hailstorm,” the queen said briskly. “Your task is simple. Enter the Diamond Caves and search until you find the frozen dragon by the river chasm. Touch one of these spears to her.” She took two gleaming, diamond-tipped spears from one of her guards and handed them to the brothers, one apiece. “Whoever returns shall take first place in the rankings. The other … we bid farewell.”

Huh. Ominous and unspecific, snarked Qibli’s voice in Winter’s head.

Narwhal stepped forward and tipped his long snout down to study his sons. “Remember, be strong,” he said. “Be vigilant. Strike first.”

“Restore our family’s rank,” added Tundra.

Narwhal’s gaze rested on Winter for a moment. “Farewell,” he said finally. “Whichever of you does not return, I know you will accept defeat with honor.”

Sounds great, Winter thought, feeling light-headed. Always wanted some defeat with a side of honor.

He had a feeling he should say something here, but Hailstorm was already pivoting and marching into the cave. Winter glanced around at the assembled IceWings one more time. Was this the last time he would see his parents? His queen and the sky?

When he’d said good-bye to Moon — had it really been forever?

He found he didn’t have anything to say to his parents after all.

Winter turned in silence and followed Hailstorm into the icy tunnel.

*  *  *

The Diamond Caves, according to the one map Winter had found, apparently stretched for miles in a kind of underground labyrinth with only one exit. Walls of ice hemmed them in on all sides, glittering blue-white in the light of their moon globes. In places, the ceiling brushed the horns on Winter’s head. In others, they had to creep along narrow ledges over dark crevasses, gripping the ice with their claws, because if they tried to fly into that vast dark space they might not find their way back before tiring and falling to their deaths.

Hailstorm glanced back at Winter once or twice with a frown, as if he’d expected Winter to choose a different path. But Winter did not want to wander this labyrinth alone, with no way to know if Hailstorm had completed the task yet or not. Better to stick together and know for sure.

They wandered for hours, perhaps in circles, perhaps in spirals ever downward. Winter was beginning to wonder if the frozen dragon even existed at all when they came out of a narrow tunnel and found the river chasm before them.

This had to be it — a wide slash in the ice ahead of them, with sheer walls that plunged down into a darkness that echoed with the rushing sound of a river.

Winter lifted his moon globe higher, scanning the cave, and felt a terrible chill run through his veins.

The cave was filled with frozen dragons. Nearly a hundred of them glittered in the moon globe’s light — some on this side of the chasm, but most of them on the other side. The one closest to him looked like an ordinary IceWing with an almost cheerful expression on his face, stepping toward Winter as though he were about to saunter out the door.

But others were frozen in positions of terror, their talons covering their faces or their wings flung out as though they were trying to leap away. And he could see a few that had clearly been fighting when they were frozen, wearing expressions of fury.

There were no other ways in or out, apart from the chasm and the tunnel behind him. Eerie blue bubbles morphed and twisted within the shining ice walls, moving as though the cave itself was breathing.

Which statue was the frozen dragon? Which one were they supposed to touch with the spear?

Hailstorm was staring around at the ice sculptures as though he were one of them. Winter took a step into the cave and noticed a sparkling pile of crushed ice near the entrance. He nudged his moon globe toward it, wondering why the pile was so big — and then he saw a dragon’s talon buried in the ice with a few of its claws snapped off.

Maybe this one had been midflight when he was frozen, and he smashed to pieces when he fell to the ground. Or maybe whoever froze him decided to finish the job by bashing his frozen corpse to smithereens.

Winter shuddered, his tail spikes rattling along the floor.

Suddenly Hailstorm leaped forward. Winter whirled and saw him racing toward a dragon on the far side of the chasm — a dragon larger than any of the others with her claws outstretched and her wings flared.

Hailstorm sailed across the gap, landed, pivoted, and struck the statue with his spear. It all happened in a moment, like a burst of lightning. By the time Winter landed beside him, Hailstorm was in battle position, brandishing the spear against whatever happened next.

A crackling sound came from the dragon.

And then, slowly, bits of ice began to break off, splintering into falling shards and shattering against the floor.

The frozen dragon comes to life, Winter realized. It made sense. Then we fight her, and she kills one of us, and the other wins. He looked around at the frozen statues and winced. Or she freezes one of us. These must be all the dragons who’ve lost the Trial.

And I could be one of them soon.

He looked back at the large frozen dragon and realized that she was not actually made of ice. She was encased inside the ice, and as her prison came apart, he saw her scales, and they were dark as a moonless night.

This was a NightWing.

She pulled in her wings and then flung out her claws, shaking the last of the ice off. Only two spots still glittered against her scales — a pair of shackles around her back ankles, although they didn’t seem to be connected to anything.

With a hiss, she turned in a circle, then whipped around to drop the full force of her glare on the princes.

“Oh, good,” she rasped in a hoarse voice. “More IceWing dragonets with spears.”

“I’m here to kill you,” Hailstorm announced, without a tremor of insecurity in his voice.

“Aren’t you all,” she said drily. “Shall we introduce ourselves first?”

Hailstorm and Winter exchanged glances. Was that normal? Conversation with a creatively imprisoned NightWing?

“I’m Prince Winter,” said Winter after an awkward pause. “And this is my brother, Hailstorm.”

“Brothers, oh my, how devastating,” said the NightWing. “Welcome to my prison. I am Foeslayer.”

Winter started back, his head reeling.

Foeslayer?

The same Foeslayer who stole the IceWing animus prince, Arctic?

The mother of Darkstalker?