LEO'S POV

Inside was enough cool stuff to keep me busy for years.

The room was about the size of the forge back at Camp Half-Blood, with bronze-topped worktables along the walls, and baskets full of ancient metalworking tools. Dozens of bronze and gold spheres like steampunk basketballs sat around in various stages of disassembly. Loose gears and wiring littered the floor. Thick metal cables ran from each table toward the back of the room, where there was an enclosed loft like a theater's sound booth. Stairs led up to the booth on either side. All the cables seemed to run into it. Next to the stairs on the left, a row of cubbyholes was filled with leather cylinders—probably ancient scroll cases.

I was about to head toward the tables when I glanced to my left and nearly jumped out of my shoes. Flanking the doorway were two armored manikins—like skeletal scarecrows made from bronze pipes, outfitted with full suits of Roman armor, shield and sword.

"Dude." I walked up to one. "These would be awesome if they worked."

Frank edged away from the manikins. "Those things are going to come alive and attack us, aren't they?"

I laughed. "Not a chance. They aren't complete." I tapped the nearest manikin's neck, where loose copper wires sprouted from underneath its breastplate. "Look, the head's wiring has been disconnected. And here, at the elbow, the pulley system for this joint is out of alignment. My guess? The Romans were trying to duplicate a Greek design, but they didn't have the skill."

Hazel arched her eyebrows. "The Romans weren't good enough at being complicated, I suppose."

"Or delicate," Frank added.

"Or sophisticated," Peri chimed in with a snicker.

"Hey, I just call it like I see it." I jiggled the manikin's head, making it nod like it was agreeing with me. "Still…a pretty impressive try. I've heard legends that the Romans confiscated the writings of Archimedes, but—"

"Archimedes?" Hazel looked baffled. "Wasn't he an ancient mathematician or something?"

I laughed like she just told the funniest joke I'd ever heard. "He was a lot more than that. He was only the most famous son of Hephaestus who ever lived."

"Son of Vulcan, huh?" Peri nodded. "Nice."

"No, Hephaestus," I corrected her. I squinted across the room at her. Did she look a little green?

Frank scratched his ear. "I've heard his name before, but how can you be sure this manikin is his design?"

"It has to be!" I said, snapping my head over to Frank. "Look, I've read all about Archimedes. He's a hero to Cabin Nine, okay don't test me! The dude was Greek, right? He lived in one of the Greek colonies in southern Italy, back before Rome got all huge and took over. Finally the Romans moved in and destroyed his city. The Roman general wanted to spare Archimedes, because he was so valuable—sort of like the Einstein of the ancient world—but some stupid Roman soldier killed him."

"There you go again," Hazel muttered. "Stupid and Roman don't always go together, Leo."

Frank grunted agreement. "How do you know all this, anyway?" he demanded. "Is there a Spanish tour guide around here?"

"No, man," I said flatly. "You can't be a demigod who's into building stuff and not know about Archimedes. The guy was seriously elite. He calculated the value of pi. He did all this math stuff we still use for engineering. He invented a hydraulic screw that could move water through pipes."

Hazel scowled. "A hydraulic screw. Excuse me for not knowing about that awesome achievement."

"He also built a death ray made of mirrors that could burn enemy ships," Leo said. "Is that awesome enough for you?"

"Oh heck yea," Peri chimed in weakly. She was laying on her side one of the work tables near the back of the room holding her belly. And now that I look at her face, she was definitely tinted green.

"Peri, you alright?" I called. She had removed her nose plugs, and instead placed a random Imperial Gold helmet on. You know the ones with the funny red plume on top.

She looked queasy but shot me a thumbs up, preferring to remain laying down.

"I saw something about that on TV," Frank challenged. "They proved it didn't work."

"Ugh, that's just because modern mortals don't know how to use Celestial bronze," I shot back. "That's the key. Archimedes also invented a massive claw that could swing on a crane and pluck enemy ships out of the water."

"Okay, that's cool," Frank admitted. "I love grabber-arm games."

"Well, there you go," Leo said. "Anyway, all his inventions weren't enough. The Romans destroyed his city. Archimedes was killed. According to legends, the Roman general was a big fan of his work, so he raided Archimedes's workshop and carted a bunch of souvenirs back to Rome. They disappeared from history, except…" I waved my hands at the stuff on the tables. "Here they are."

"Metal basketballs?" Hazel asked.

I couldn't believe that they didn't appreciate what they were looking at, but I tried my best to contain my irritation.

"Guys, Archimedes constructed spheres. The Romans couldn't figure them out. They thought they were just for telling time or following constellations, because they were covered with pictures of stars and planets. But that's like finding a rifle and thinking it's a walking stick."

"Leo, the Romans were top-notch engineers," Hazel reminded me. "They built aqueducts, roads—"

Siege weapons," Frank added. "Public sanitation."

"Yeah, fine," I said. "But Archimedes was in a class by himself. His spheres could do all sorts of things, only nobody is sure…"

Suddenly I got an idea so incredible that my nose burst into flames. I patted it out as quickly as possible. Man, it was embarrassing when that happened.

My cheeks burned crimson, and I couldn't bear to look Peri's direction in case she had seen. Geez I get fired up so much in front of her already as it is.

I ran to the row of cubbyholes and examined the markings on the scroll cases. "Oh, gods. This is it!"

I gingerly lifted out one of the scrolls. I wasn't great at Ancient Greek, but I could tell the inscription on the case read On Building Spheres.

"Guys, this is the lost book!" My hands were shaking from excitement. "Archimedes wrote this, describing his construction methods, but all the copies were lost in ancient times. If I can translate this…"

The possibilities were endless. For me, the quest had now totally taken on a new dimension. I had to get the spheres and scrolls safely out of here. I had to protect this stuff until I could get it back to Bunker 9 and study it.

"The secrets of Archimedes," I murmured. "Guys, this is bigger than Daedalus's laptop. If there's a Roman attack on Camp Half-Blood, these secrets could save the camp. They might even give us an edge over Gaea and the giants!"

Hazel and Frank glanced at each other skeptically.

"Okay," Hazel said. "We didn't come here for a scroll, but I guess we can take it with us."

"Assuming," Frank added, "that you don't mind sharing its secrets with us stupid uncomplicated Romans."

"What?" I stared at him blankly. "No. Look, I didn't mean to insult— Ah, never mind. The point is this is good news!"

For the first time in days, I felt genuinely hopeful.

Naturally, that's when everything went wrong.

On the table next to Hazel and Frank, one of the orbs clicked and whirred. A row of spindly legs extended from its equator. The orb stood, and two bronze cables shot out of the top, hitting Hazel and Frank like Taser wires. My friends both crumpled to the floor.

I lunged to help them, but the two armored manikins that couldn't possibly move did move. They drew their swords and stepped toward me.

My eyes flitted to where Peri had just been lying on a worktable in the back of the room. She had a bronze sword in her hand, but she was clutching her stomach and looked as though she could barely walk, let alone fight.

However it seemed as though the manakins hadn't noticed her yet, so I used that to my advantage.

The manakin on the left turned its crooked helmet, which was shaped like a wolf's head. Despite the fact that it had no face or mouth, a familiar hollow voice spoke from behind its visor.

"You cannot escape us, Leo Valdez," it said. "We do not like possessing machines, but they are better than tourists. You will not leave here alive."