Finally Leo told him to go belowdecks and secure everything for departure. He wasn’t doing any good beating himself up.

The six demigods gathered on the quarterdeck and gazed at the distant column of dust still rising from the site of the implosion.

Leo rested his hand on the Archimedes sphere, which now sat on the helm, ready to be installed. He should have been excited. It was the biggest discovery of his life—even bigger than Bunker 9. If he could decipher Archimedes’s scrolls, he could do amazing things. He hardly dared to hope, but he might even be able to build a new control disk for a certain dragon friend of his.

Still, the price had been too high.

He could almost hear Nemesis laughing. I told you we could do business, Leo Valdez.

He had opened the fortune cookie. He’d gotten the access code for the sphere and saved Frank and Hazel. But the sacrifice had been Percy and Annabeth. Leo was sure of it.

“It’s my fault,” he said miserably.

The others stared at him. Only Hazel seemed to understand. She’d been with him at the Great Salt Lake.

“No,” she insisted. “No, this is Gaea’s fault. It had nothing to do with you.”

Leo wanted to believe that, but he couldn’t. They’d started this voyage with Leo messing up, firing on New Rome. They’d ended in old Rome with Leo breaking a cookie and paying a price much worse than an eye.

“Leo, listen to me.” Hazel gripped his hand. “I won’t allow you to take the blame. I couldn’t bear that after—after Sammy…”

She choked up, but Leo knew what she meant. His bisabuelo had blamed himself for Hazel’s disappearance. Sammy had lived a good life, but he’d gone to his grave believing that he’d spent a cursed diamond and doomed the girl he loved.

Leo didn’t want to make Hazel miserable all over again, but this was different. True success requires sacrifice. Leo had chosen to break that cookie. Percy and Annabeth had fallen into Tartarus. That couldn’t be a coincidence.

Nico di Angelo shuffled over, leaning on his black sword. “Leo, they’re not dead. If they were, I could feel it.”

“How can you be sure?” Leo asked. “If that pit really led to…you know…how could you sense them so far away?”

Nico and Hazel shared a look, maybe comparing notes on their Hades/Pluto death radar. Leo shivered. Hazel had never seemed like a child of the Underworld to him, but Nico di Angelo—that guy was creepy.

“We can’t be one hundred percent sure,” Hazel admitted. “But I think Nico is right. Percy and Annabeth are still alive…at least, so far.”

Jason pounded his fist against the rail. “I should’ve been paying attention. I could have flown down and saved them.”

“Me, too,” Frank moaned. The big dude looked on the verge of tears.

Piper put her hand on Jason’s back. “It’s not your fault, either of you. You were trying to save the statue.”

“She’s right,” Nico said. “Even if the pit hadn’t been buried, you couldn’t have flown into it without being pulled down. I’m the only one who has actually been into Tartarus. It’s impossible to describe how powerful that place is. Once you get close, it sucks you in. I never stood a chance.”

Frank sniffled. “Then Percy and Annabeth don’t stand a chance either?”

Nico twisted his silver skull ring. “Percy is the most powerful demigod I’ve ever met. No offense to you guys, but it’s true. If anybody can survive, he will, especially if he’s got Annabeth at his side. They’re going to find a way through Tartarus.”

Jason turned. “To the Doors of Death, you mean. But you told us it’s guarded by Gaea’s most powerful forces. How could two demigods possibly—?”

“I don’t know,” Nico admitted. “But Percy told me to lead you guys to Epirus, to the mortal side of the doorway. He’s planning on meeting us there. If we can survive the House of Hades, fight our way through Gaea’s forces, then maybe we can work together with Percy and Annabeth and seal the Doors of Death from both sides.”

“And get Percy and Annabeth back safely?” Leo asked.

“Maybe.”

Leo didn’t like the way Nico said that, as if he wasn’t sharing all his doubts. Besides, Leo knew something about locks and doors. If the Doors of Death needed to be sealed from both sides, how could they do that unless someone stayed in the Underworld, trapped?

Nico took a deep breath. “I don’t know how they’ll manage it, but Percy and Annabeth will find a way. They’ll journey through Tartarus and find the Doors of Death. When they do, we have to be ready.”

“It won’t be easy,” Hazel said. “Gaea will throw everything she’s got at us to keep us from reaching Epirus.”

“What else is new?” Jason sighed.

Piper nodded. “We’ve got no choice. We have to seal the Doors of Death before we can stop the giants from raising Gaea. Otherwise her armies will never die. And we’ve got to hurry. The Romans are in New York. Soon, they’ll be marching on Camp Half-Blood.”

“We’ve got one month at best,” Jason added. “Ephialtes said Gaea would awaken in exactly one month.”

Leo straightened. “We can do it.”

Everyone stared at him.

“The Archimedes sphere can upgrade the ship,” he said, hoping he was right. “I’m going to study those ancient scrolls we got. There’s got to be all kinds of new weapons I can make. We’re going to hit Gaea’s armies with a whole new arsenal of hurt.”

At the prow of the ship, Festus creaked his jaw and blew fire defiantly.

Jason managed a smile. He clapped Leo on the shoulder.

“Sounds like a plan, Admiral. You want to set the course?”

They kidded him, calling him Admiral, but for once Leo accepted the title. This was his ship. He hadn’t come this far to be stopped.

They would find this House of Hades. They’d take the Doors of Death. And by the gods, if Leo had to design a grabber arm long enough to snatch Percy and Annabeth out of Tartarus, then that’s what he would do.

Nemesis wanted him to wreak vengeance on Gaea? Leo would be happy to oblige. He was going to make Gaea sorry she had ever messed with Leo Valdez.

“Yeah.” He took one last look at the cityscape of Rome, turning bloodred in the sunset. “Festus, raise the sails. We’ve got some friends to save.”