He started small. He focused on one reasonably intact gold sphere down in the main room. The gold sphere shuddered. It grew a tripod of legs and clattered over to the Taser ball. A tiny circular saw popped out of the gold sphere’s head, and it began cutting into Taser ball’s brain.

Leo tried to activate another orb. This one burst in a small mushroom cloud of bronze dust and smoke.

“Oops,” he muttered. “Sorry, Archimedes.”

“What are you doing?” Wolf Head demanded. “Stop your foolishness and surrender!”

“Oh, yes, I surrender!” Leo said. “I’m totally surrendering!”

He tried to take control of a third orb. That one broke too. Leo felt bad about ruining all these ancient inventions, but this was life or death. Frank had accused him of caring more for machines than people, but if it came down to saving old spheres or his friends, there was no choice.

The fourth try went better. A ruby-encrusted orb popped its top and helicopter blades unfolded. Leo was glad Buford the table wasn’t here—he would’ve fallen in love. The ruby orb spun into the air and sailed straight for the cubbyholes. Thin golden arms extended from its middle and snapped up the precious scroll cases.

“Enough!” Wolf Head yelled. “I will destroy the—”

He turned in time to see the ruby sphere take off with the scrolls. It zipped across the room and hovered in the far corner.

“What?!” Wolf Head cried. “Kill the prisoners!”

He must have been talking to the Taser ball. Unfortunately, Taser ball was in no shape to comply. Leo’s gold sphere was sitting on top of its sawed-open head, picking through its gears and wires like it was scooping out a pumpkin.

Thank the gods, Hazel and Frank began to stir.

“Bah!” Wolf Head gestured to Lion Head at the opposite gate. “Come! We will destroy the demigods ourselves.”

“I don’t think so, guys.” Leo turned toward Lion Head. His hands worked the control sphere, and he felt a shock travel through the floor.

Lion Head shuddered and lowered his sword.

Leo grinned. “You’re in Leo World, now.”

Lion Head turned and stormed down the stairs. Instead of advancing on Hazel and Leo, he marched up the opposite stairs and faced his comrade.

“What are you doing?” Wolf Head demanded. “We have to—”

BLONG!

Lion Head slammed his shield into Wolf Head’s chest. He smashed the pommel of his sword into his comrade’s helmet, so Wolf Head became Flat, Deformed, Not Very Happy Wolf Head.

“Stop that!” Wolf Head demanded.

“I cannot!” Lion Head wailed.

Leo was getting the hang of it now. He commanded both suits of armor to drop their swords and shields and slap each other repeatedly.

“Valdez!” called Wolf Head in a warbling voice. “You will die for this!”

“Yeah,” Leo called out. “Who’s possessing who now, Casper?”

The machine men tumbled down the stairs, and Leo forced them to jitterbug like 1920s flappers. Their joints began smoking. The other spheres around the room began to pop. Too much energy was surging through the ancient system. The control sphere in Leo’s hand grew uncomfortably warm.

“Frank, Hazel!” Leo shouted. “Take cover!”

His friends were still dazed, staring in amazement at the jitterbugging metal guys, but they got his warning. Frank pulled Hazel under the nearest table and shielded her with his body.

One last twist of the sphere, and Leo sent a massive jolt through the system. The armored warriors blew apart. Rods, pistons, and bronze shards flew everywhere. On all the tables, spheres popped like hot soda cans. Leo’s gold sphere froze. His flying ruby orb dropped to the floor with the scroll cases.

The room was suddenly quiet except for a few random sparks and sizzles. The air smelled like burning car engines. Leo raced down the stairs and found Frank and Hazel safe under their table. He had never been so happy to see those two hugging.

“You’re alive!” he said.

Hazel’s left eye twitched, maybe from the Taser shock. Otherwise she looked okay. “Uh, what exactly happened?”

“Archimedes came through!” Leo said. “Just enough power left in those old machines for one final show. Once I had the access code, it was easy.”

He patted the control sphere, which was steaming in a bad way. Leo didn’t know if it could be fixed, but at the moment he was too relieved to care.

“The eidolons,” Frank said. “Are they gone?”

Leo grinned. “My last command overloaded their kill switches—basically locked down all their circuits and melted their cores.”

“In English?” Frank asked.

“I trapped the eidolons inside the wiring,” Leo said. “Then I melted them. They won’t be bothering anyone again.”

Leo helped his friends to their feet.

“You saved us,” Frank said.

“Don’t sound so surprised.” Leo glanced around the destroyed workshop. “Too bad all this stuff got wrecked, but at least I salvaged the scrolls. If I can get them back to Camp Half-Blood, maybe I can learn how to recreate Archimedes’s inventions.”

Hazel rubbed the side of her head. “But I don’t understand. Where is Nico? That tunnel was supposed to lead us to Nico.”

Leo had almost forgotten why they’d come down here in the first place. Nico obviously wasn’t here. The place was a dead end. So why… ?

“Oh.” He felt like there was a buzz-saw sphere on his own head, pulling out his wires and gears. “Hazel, how exactly were you tracking Nico? I mean, could you just sense him nearby because he was your brother?”

She frowned, still looking a bit wobbly from her electric shock treatment. “Not—not totally. Sometimes I can tell when he’s close, but, like I said, Rome is so confusing, so much interference because of all the tunnels and caves—”

“You tracked him with your metal-finding senses,” Leo guessed. “His sword?”

She blinked. “How did you know?”

“You’d better come here.” He led Hazel and Frank up to the control room and pointed to the black sword.

“Oh. Oh, no.” Hazel would’ve collapsed if Frank hadn’t caught her. “But that’s impossible! Nico’s sword was with him in the bronze jar. Percy saw it in his dream!”

“Either the dream was wrong,” Leo said, “or the giants moved the sword here as a decoy.”

“So this was a trap,” Frank said. “We were lured here.”

“But why?” Hazel cried. “Where’s my brother?”

A hissing sound filled the control booth. At first, Leo thought the eidolons were back. Then he realized the bronze mirror on the table was steaming.

Ah, my poor demigods. The sleeping face of Gaea appeared in the mirror. As usual, she spoke without moving her mouth, which could only have been creepier if she’d had a ventriloquism puppet. Leo hated those things.

You had your choice, Gaea said. Her voice echoed through the room. It seemed to be coming not just from the mirror, but from the stone walls as well.

Leo realized she was all around them. Of course. They were in the earth. They’d gone to all the trouble of building the Argo II so they could travel by sea and air, and they’d ended up in the earth anyway.

I offered salvation to all of you, Gaea said. You could have turned back. Now it is too late. You’ve come to the ancient lands where I am strongest—where I will wake.

Leo pulled a hammer from his tool belt. He whacked the mirror. Being metal, it just quivered like a tea tray, but it felt good to smash Gaea in the nose.

“In case you haven’t noticed, Dirt Face,” he said, “your little ambush failed. Your three eidolons got melted in bronze, and we’re fine.”

Gaea laughed softly. Oh, my sweet Leo. You three have been separated from your friends. That was the whole point.

The workshop door slammed shut.

You are trapped in my embrace, Gaea said. Meanwhile, Annabeth Chase faces her death alone, terrified and crippled, at the hands of her mother’s greatest enemy.

The image in the mirror changed. Leo saw Annabeth sprawled on the floor of a dark cavern, holding up her bronze knife as if warding off a monster. Her face was gaunt. Her leg was wrapped up in some sort of splint. Leo couldn’t see what she was looking at, but it was obviously something horrible. He wanted to believe the image was a lie, but he had a bad feeling it was real, and it was happening right now.

The others, Gaea said, Jason Grace, Piper McLean, and my dear friend Percy Jackson—they will perish within minutes.

The scene changed again. Percy was holding Riptide, leading Jason and Piper down a spiral staircase into the darkness.

Their powers will betray them, Gaea said. They will die in their own elements. I almost hoped they would survive. They would have made a better sacrifice. But alas, Hazel and Frank, you will have to do. My minions will collect you shortly and bring you to the ancient place. Your blood will awaken me at last. Until then, I will allow you to watch your friends perish. Please…enjoy this last glimpse of your failed quest.

Leo couldn’t stand it. His hand glowed white hot. Hazel and Frank scrambled back as he pressed his palm against the mirror and melted it into a puddle of bronze goo.

The voice of Gaea went silent. Leo could only hear the roar of blood in his ears. He took a shaky breath.

“Sorry,” he told his friends. “She was getting annoying.”

“What do we do?” Frank asked. “We have to get out and help the others.”

Leo scanned the workshop, now littered with smoking pieces of broken spheres. His friends still needed him. This was still his show. As long as he had his tool belt, Leo Valdez wasn’t going to sit around helplessly watching the Demigod Death Channel.

“I’ve got an idea,” he said. “But it’s going to take all three of us.”

He started telling them the plan.

Chapter 41

Piper tried to make the best of the situation.

Once she and Jason had gotten tired of pacing the deck, listening to Coach Hedge sing “Old MacDonald” (with weapons instead of animals), they decided to have a picnic in the park.

Hedge grudgingly agreed. “Stay where I can see you.”

“What are we, kids?” Jason asked.

Hedge snorted. “Kids are baby goats. They’re cute, and they have redeeming social value. You are definitely not kids.”

They spread their blanket under a willow tree next to a pond. Piper turned over her cornucopia and spilled out an entire meal—neatly wrapped sandwiches, canned drinks, fresh fruit, and (for some reason) a birthday cake with purple icing and candles already lit.

She frowned. “Is it someone’s birthday?”

Jason winced. “I wasn’t going to say anything.”

“Jason!”

“There’s too much going on,” he said. “And honestly…before last month, I didn’t even know when my birthday was. Thalia told me the last time she was at camp.”

Piper wondered what that would be like—not even knowing the day you were born. Jason had been given to Lupa the wolf when he was only two years old. He’d never really known his mortal mom. He’d only been reunited with his sister last winter.