The chamber rumbled. Another stela crashed to the floor and shattered.

“The House of Hades is unstable,” Hecate said. “Leave now. We shall meet again.”

The goddess dissolved. The Mist evaporated.

“She’s friendly,” Percy grumbled.

The others turned toward him and Annabeth, as if just realizing they were there.

“Dude.” Jason gave Percy a bear hug.

“Back from Tartarus!” Leo whooped. “That’s my peeps!”

Piper threw her arms around Annabeth and cried.

Frank ran to Hazel. He gently folded his arms around her. “You’re hurt,” he said.

“Ribs probably broken,” she admitted. “But Frank—what happened to your arm?”

He managed a smile. “Long story. We’re alive. That’s what matters.”

She was so giddy with relief it took her a moment to notice Nico, standing by himself, his expression full of pain and conflict.

“Hey,” she called to him, beckoning with her good arm.

He hesitated, then came over and kissed her forehead. “I’m glad you’re okay,” he said. “The ghosts were right. Only one of us made it to the Doors of Death. You…you would have made Dad proud.”

She smiled, cupping her hand gently to his face. “We couldn’t have defeated Clytius without you.”

She brushed her thumb under Nico’s eye and wondered if he had been crying. She wanted so badly to understand what was going on with him—what had happened to him over the last few weeks. After all they’d just been through, Hazel was more grateful than ever to have a brother.

Before she could say that, the ceiling shuddered. Cracks appeared in the remaining tiles. Columns of dust spilled down.

“We’ve got to get out of here,” Jason said. “Uh, Frank…?”

Frank shook his head. “I think one favor from the dead is all I can manage today.”

“Wait, what?” Hazel asked.

Piper raised her eyebrows. “Your unbelievable boyfriend called in a favor as a child of Mars. He summoned the spirits of some dead warriors, made them lead us here through…um, well, I’m not sure, actually. The passages of the dead? All I know is that it was very, very dark.”

To their left, a section of the wall split. Two ruby eyes from a carved stone skeleton popped out and rolled across the floor.

“We’ll have to shadow-travel,” Hazel said.

Nico winced. “Hazel, I can barely manage that with only myself. With seven more people—”

“I’ll help you.” She tried to sound confident. She’d never shadow-traveled before, had no idea if she could; but after working with the Mist, altering the Labyrinth—she had to believe it was possible.

An entire section of tiles peeled loose from the ceiling.

“Everyone, grab hands!” Nico yelled.

They made a hasty circle. Hazel envisioned the Greek countryside above them. The cavern collapsed, and she felt herself dissolving into shadow.

They appeared on the hillside overlooking the River Acheron. The sun was just rising, making the water glitter and the clouds glow orange. The cool morning air smelled of honeysuckle.

Hazel was holding hands with Frank on her left, Nico on her right. They were all alive and mostly whole. The sunlight in the trees was the most beautiful thing she’d ever seen. She wanted to live in that moment—free of monsters and gods and evil spirits.

Then her friends began to stir.

Nico realized that he was holding Percy’s hand and quickly let go.

Leo staggered backward. “You know…I think I’ll sit down.”

He collapsed. The others joined him. The Argo II still floated over the river a few hundred yards away. Hazel knew that they should signal Coach Hedge and tell him they were alive. Had they been in the temple all night? Or several nights? But at the moment, the group was too tired to do anything except sit and relax and marvel at the fact that they were okay.

They began to exchange stories.

Frank explained what had happened with the ghostly legion and the army of monsters—how Nico had used the scepter of Diocletian, and how bravely Jason and Piper had fought.

“Frank is being modest,” Jason said. “He controlled the entire legion. You should’ve seen him. Oh, by the way…” Jason glanced at Percy. “I resigned my office, gave Frank a field promotion to praetor. Unless you want to contest that ruling.”

Percy grinned. “No argument here.”

“Praetor?” Hazel stared at Frank.

He shrugged uncomfortably. “Well…yeah. I know it seems weird.”

She tried to throw her arms around him, then winced as she remembered her busted ribs. She settled for kissing him. “It seems perfect.”

Leo clapped Frank on the shoulder. “Way to go, Zhang. Now you can order Octavian to fall on his sword.”

“Tempting,” Frank agreed. He turned apprehensively to Percy. “But, you guys…Tartarus has to be the real story. What happened down there? How did you…?”

Percy laced his fingers through Annabeth’s.

Hazel happened to glance at Nico and saw pain in his eyes. She wasn’t sure, but maybe he was thinking how lucky Percy and Annabeth were to have each other. Nico had gone through Tartarus alone.

“We’ll tell you the story,” Percy promised. “But not yet, okay? I’m not ready to remember that place.”

“No,” Annabeth agreed. “Right now…” She gazed toward the river and faltered. “Uh, I think our ride is coming.”

Hazel turned. The Argo II veered to port, its aerial oars in motion, its sails catching the wind. Festus’s head glinted in the sunlight. Even from a distance, Hazel could hear him creaking and clanking in jubilation.

“That’s my boy!” Leo yelled.

As the ship got closer, Hazel saw Coach Hedge standing at the prow.

“About time!” the coach yelled down. He was doing his best to scowl, but his eyes gleamed as if maybe, just maybe, he was happy to see them. “What took you so long, cupcakes? You kept your visitor waiting!”

“Visitor?” Hazel murmured.

At the rail next to Coach Hedge, a dark-haired girl appeared wearing a purple cloak, her face so covered with soot and bloody scratches that Hazel almost didn’t recognize her.

Reyna had arrived.

PERCY STARED AT THE ATHENA PARTHENOS, waiting for it to strike him down.

Leo’s new mechanical hoist system had lowered the statue onto the hillside with surprising ease. Now the forty-foot-tall goddess gazed serenely over the River Acheron, her gold dress like molten metal in the sun.

“Incredible,” Reyna admitted.

She was still red-eyed from crying. Soon after she’d landed on the Argo II, her pegasus Scipio had collapsed, overwhelmed by poisoned claw marks from a gryphon attack the night before. Reyna had put the horse out of his misery with her golden knife, turning the pegasus into dust that scattered in the sweet-smelling Greek air. Maybe not a bad end for a flying horse, but Reyna had lost a loyal friend. Percy figured that she’d given up too much in her life already.

The praetor circled the Athena Parthenos warily. “It looks newly made.”

“Yeah,” Leo said. “We brushed off the cobwebs, used a little Windex. It wasn’t hard.”

The Argo II hovered just overhead. With Festus keeping watch for threats on the radar, the entire crew had decided to eat lunch on the hillside while they discussed what to do. After the last few weeks, Percy figured they’d earned a good meal together—really anything that wasn’t fire water or drakon meat soup.

“Hey, Reyna,” Annabeth called. “Have some food. Join us.”

The praetor glanced over, her dark eyebrows furrowed, as if join us didn’t quite compute. Percy had never seen Reyna without her armor before. It was on board the ship, being repaired by Buford the Wonder Table. She wore a pair of jeans and a purple Camp Jupiter T-shirt and looked almost like a normal teenager—except for the knife at her belt and that guarded expression, like she was ready for an attack from any direction.

“All right,” she said finally.

They scooted over to make room for her in the circle. She sat cross-legged next to Annabeth, picked up a cheese sandwich, and nibbled at the edge.

“So,” Reyna said. “Frank Zhang…praetor.”

Frank shifted, wiping crumbs from his chin. “Well, yeah. Field promotion.”

“To lead a different legion,” Reyna noted. “A legion of ghosts.”

Hazel put her arm protectively through Frank’s. After an hour in sick bay, they both looked a lot better; but Percy could tell they weren’t sure what to think about their old boss from Camp Jupiter dropping in for lunch.

“Reyna,” Jason said, “you should’ve seen him.”

“He was amazing,” Piper agreed.

“Frank is a leader,” Hazel insisted. “He makes a great praetor.”

Reyna’s eyes stayed on Frank, like she was trying to guess his weight. “I believe you,” she said. “I approve.”

Frank blinked. “You do?”

Reyna smiled dryly. “A son of Mars, the hero who helped to bring back the eagle of the legion…I can work with a demigod like that. I’m just wondering how to convince the Twelfth Fulminata.”

Frank scowled. “Yeah. I’ve been wondering the same thing.”

Percy still couldn’t get over how much Frank had changed. A “growth spurt” was putting it mildly. He was at least three inches taller, less pudgy, and more bulky, like a linebacker. His face looked sturdier, his jawline more rugged. It was as if Frank had turned into a bull and then back to human, but he’d kept some of the bullishness.

“The legion will listen to you, Reyna,” Frank said. “You made it here alone, across the ancient lands.”

Reyna chewed her sandwich as if it were cardboard. “In doing so, I broke the laws of the legion.”

“Caesar broke the law when he crossed the Rubicon,” Frank said. “Great leaders have to think outside the box sometimes.”

She shook her head. “I’m not Caesar. After finding Jason’s note in Diocletian’s Palace, tracking you down was easy. I only did what I thought was necessary.”

Percy couldn’t help smiling. “Reyna, you’re too modest. Flying halfway across the world by yourself to answer Annabeth’s plea, because you knew it was our best chance for peace? That’s pretty freaking heroic.”

Reyna shrugged. “Says the demigod who fell into Tartarus and found his way back.”

“He had help,” Annabeth said.

“Oh, obviously,” Reyna said. “Without you, I doubt Percy could find his way out of a paper bag.”

“True,” Annabeth agreed.

“Hey!” Percy complained.

The others started laughing, but Percy didn’t mind. It felt good to see them smile. Heck, just being in the mortal world felt good, breathing un-poisonous air, enjoying actual sunshine on his back.

Suddenly he thought of Bob. Tell the sun and stars hello for me.