The rocky, scorched slope fell away behind them, and ahead stretched a gentle plain of grass beneath a bright sun. The storm still raged below, thunder grumbling, but this green expanse floated peacefully above it all, a whole different world. Here, breezes tumbled through the grass, gentle as kittens.

Looking back, Nox saw the crown of the thunderhead surrounding them like a dark, angry sea, swirling with malevolent mists, nibbling at the edges of the island.

He took a first hesitant step into that green expanse, only to hear the grass all around them start rustling. He tensed, expecting trouble, as all at once, thousands of glowing lights burst up. Freezing in place, his eyes wide, Nox watched as their shimmering wings filled the air.

“Moonmoths!” exclaimed Ellie.

Nox thought at once of the forest glade where he’d first seen a pack of the little moths break from their chrysalises and take flight. These were the same, their papery wings and velvety antennae softly gleaming with light. He and Gussie and Ellie watched in awe as the moonmoths swirled around them in a dazzling murmuration, before fluttering down into the grass again.

“So this is where they go,” Gussie murmured. “Guess that’s one ancient mystery solved. They must lay their eggs on the ground before migrating back to the sky.”

“If only Twig could be here,” sighed Ellie. “He’d love to see them again.”

Reminded of their mission, Nox nodded briskly. “Right. Let’s find a skystone and get out of here. Those moths make this place even creepier.”

“There’s a building over that way,” Gussie said. “Or … there used to be.”

“C’mon,” said Ellie. “Let’s check it out.”

A current of unease rolled through Nox. “Last time, we saw skystones under the floating island, not on top of it. Shouldn’t we be going the other way?”

“And miss a chance to find out more about this place?” said Gussie, who was apparently completely on Ellie’s side now.

“She’s right,” said Ellie. “Besides, do you see any gargols up here?”

“We heard one less than five minutes ago!” he protested. “What’s to stop them from coming up here?”

“Scared?”

Nox nearly pulled his hair out. “Of course I’m scared! Only an idiot wouldn’t be scared! We’re miles above the ground, riding atop a storm filled with—aaaand you’re walking away.”

Muttering beneath his breath about the stubbornness of Sparrows, he jogged to catch up to the girls. Moonmoths fluttered irritably out of his path, trailing pale, glowing dust.

The building turned out to be a crumbling disappointment. Whatever the place had been, it was once vast and no doubt impressive, but there wasn’t much left now except weathered blocks of stone, laid out in a rectangle. Grass, chunks of masonry, and little else remained.

“It’s gone,” he said. “Nothing to see. Can we get back to our actual mission now?”

“Wait.” Gussie rubbed her cheek, thinking. Then she walked across the ruin and stopped. “Aha! It’s not gone. It’s just sunken into the ground. I figured that might be case. Centuries of erosion by storms and wind weakened the foundations, and the whole thing caved in on itself.”

“Great. Mystery solved. Now let’s—”

All at once, Gussie vanished.

Nox and Ellie rushed forward, staring down the hole the Falcon girl had dropped into.

“This way!” Gussie called, the echo of her voice indicating she’d found some kind of underground chamber.

“I don’t like this, Ellie.”

“Yeah, but … aren’t you a little curious?” She grinned and dropped down into the dark.

“Twig is waiting for us, you know!” he shouted into the hole.

No one answered. He saw a flare of light below as Ellie lit something.

Grumbling, Nox shimmied himself onto the edge of the opening, then dropped.

He flapped his wings thrice before he landed on a stone floor. Ellie and Gussie were walking away, Ellie with one of Jaff’s candles in her hand in a little brass holder.

“Wait!” Nox called, running after.

They walked down a long, large passageway, easily wide enough to spread their wings in. The walls were solid stone brick, and the sound of dripping water echoed in the darkness ahead.

“This place is huge,” said Ellie.

“It’s definitely constructed the same way as the towers we found on the ground,” said Gussie, rubbing the stone walls. “This has to be Tirelas.”

Ellie smiled at her, linking arms. “So you believe me now, Agustina Berel?”

Gussie snorted and pulled her arm away. “I haven’t made up my mind about all of it yet. Let’s gather more information before you get all smug.”

The deeper they delved into the ruin, the more Nox began to relax. This place wasn’t so bad. It wasn’t teeming with gargols, anyway. At least not yet. And it was kind of fascinating.

“Murals!” Ellie said, passing the torch over massive mosaics on the walls. “Just like in the towers.”

“Better preserved too.” Gussie tapped the tiles. “And different scenes.”

Instead of happy people flying around, these murals depicted grandly dressed men and women in long robes.

“Kings and queens of Tirelas, I bet,” Gussie said. “See the crowns on their heads? Could this have been some kind of royal palace?”

“Why are they all on fire?” asked Ellie.

Each of the figures stood in a ring of flames, eyes closed and wings spread.

Nox shrugged. “Looks like some kind of funeral ritual.”

“And yet …” Gussie tapped her lip. “See the inscriptions below them?” She ran her fingers over the strange letters carved into the wall. “ ‘Birth of Aronika, Queen. Birth of Aronidas, King. Birth of …’ Well, you get the idea.”

“Birth?” echoed Ellie. “I thought it was a funeral thing.”

“Maybe it means birth into the next life or something.”

“Check out their wings.”

Flakes of gold in the paint caught the light, and the murals seemed to spring to life. The wings especially began to glow, the red and orange paint of the feathers bright with bits of reflective gold.

“So beautiful,” murmured Ellie, running her hand over the tiles. “Their wings are like living fire. Wonder what clan they were?”

“Orioles?” said Gussie. “Or some branch of the Parrot clan?”

“Hmm,” said Ellie, looking unpersuaded.

When they came to an old cave-in, the passageway blocked by rubble, they doubled back until they found a door they’d missed. It was cracked open just enough to shimmy through.

“Great skies,” Ellie gasped.

Her candle wasn’t nearly bright enough to illuminate the chamber in which they now found themselves. The air was cooler, less stale than in the corridor outside. Nox took a few steps forward, each footfall sending out a chain of echoes.

Columns vaulted upward, holding up a ceiling lost in shadow. The floor was tiled in more mosaics, bright sunbursts with more flecks of gold shimmering in the paint.

Nox leaned forward, peering hard into the darkness ahead.

“Put out the candle, Ellie,” he said quietly.

“Why? What is it?”

“Just put it out.”

Ellie blew on the candle, extinguishing the flame.

At once, the chamber lit up.

Even Nox gasped as blue light shone from every corner, from the ceiling, from high on the columns. It was as bright as if the full moon were shining down, enough to turn the room silver.

Skystones.

They were everywhere, in every shape, size, and form.

They were worked into the mosaic floor, inlaid into carvings on the columns, glowing blue swirls of light. From the arched ceiling hung enormous chandeliers with hundreds of crystals dangling like teardrops. Along the walls, large, uncut slabs of the stuff rose from recessed channels that might have once been full of water.

The chamber was massive, even larger than Nox had imagined. Twelve rows of columns, every one covered in glowing patterns of blue skystone, stretched to the right and left, and marched away toward the far end of the room.

There, in the distance, rose the brightest cluster of skystones, rising in great crystals around a grand marble throne.

Nox walked forward as if in a dream.

He doubted even King Garion had a seat as fancy as this one. The back of the chair was sculpted like a magnificent set of wings. The skystones framing it were so smooth and polished that Nox’s own reflection stared back at him.

The throne was set atop thirteen wide steps, their edges worn smooth. Not, he guessed, by time but by pairs of feet going up and down. Across the top step was engraved a line of script. Skystone had been inlaid into the letters, so the words glowed blue.

“ ‘Here am I of ashes born,’ ” said Gussie, reading the inscription, “ ‘ruler of all Tirelas, uniter of the people of the sky, crowned chief of the royal clan … Phoenix.’ ”

“Phoenix clan?” said Ellie. “Never heard of a Phoenix clan before.”

“They must have been to Tirelas what the Eagles are to the Clandoms.”

“You mean spoiled, corrupt rats in fancy clothes?” Nox snorted. “Maybe it’s a good thing they’re not around anymore.”

“Who says they aren’t?” said Ellie. “If there’s one thing this place is telling me, it’s that we don’t know what we don’t know. I mean, clearly this isn’t just some gargol nest. It was once a great civilization, just like Granna said. This place was ours. And we were pushed out of it by the gargols.” Her voice rose, shaking with anger. “Truehome. That’s what the Restless called this place, even if they didn’t know the whole story. And the gargols took it from us—our true homes, our true history!”

“Shh,” Nox warned. “We don’t know that there aren’t gargols still creeping around this place. You wanna start a whole new war with them?”

“Start?” Ellie stared at him. “Nox, don’t you get it? The war never ended! We’re still fighting it, a thousand years later. And the tide is turning—against us. Gargols attacking in daylight, tearing through the walls that once protected us. Don’t either of you see what’s happening? They want to wipe us out. They started here, on these islands, which were once ours, they drove us to the ground, and now they’re still hunting us!”

“Let’s not jump to conclusions about motives,” said Gussie. “We still don’t know—”

SCREEEEECHHHHH!

The sound ripped through the throne room, rattling the crystals.

“They found us!” Ellie gasped.

“Back to the door!” said Gussie.

“Wait.” Nox launched into the air. “Don’t forget about Twig!”

He flew to the closest chandelier and grabbed hold of one of the skystones dangling from it. It broke off with a tug. “Got one!”

“Here,” said Ellie, hovering beside him and holding open her belt satchel. Then she grabbed another crystal and pulled it free.

“What are you doing? We only need—”

“Don’t be stupid, Nox. This is our chance, don’t you see? If these things can heal wingrot, we’re taking as many as we can carry back home with us.”

Relenting, he helped her fill her bag, then his own and Gussie’s. Once they had as many as they could fit, they winged toward the door.

Only to have it explode in their faces.