“Siege weapons,” Frank added. “Public sanitation.”

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

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

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

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

“Guys, this is the lost book!” His hands were shaking. “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 Leo, the quest had now totally taken on a new dimension. Leo had to get the spheres and scrolls safely out of here. He had to protect this stuff until he could get it back to Bunker 9 and study it.

“The secrets of Archimedes,” he 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?” Leo 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, Leo felt really 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. Leo’s friends both crumpled to the floor.

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

The one 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.”

Chapter 39

Leo agreed with Nemesis about one thing: good luck was a sham. At least when it came to Leo’s luck.

Last winter he had watched in horror while a family of Cyclopes prepared to roast Jason and Piper with hot sauce. He’d schemed his way out of that one and saved his friends all by himself, but at least he’d had time to think.

Now, not so much. Hazel and Frank had been knocked out by the tendrils of a possessed steampunk bowling ball. Two suits of armor with bad attitudes were about to kill him.

Leo couldn’t blast them with fire. Suits of armor wouldn’t be hurt by that. Besides, Hazel and Frank were too close. He didn’t want to burn them, or accidentally hit the piece of firewood that controlled Frank’s life.

On Leo’s right, the suit of armor with a lion’s head helmet creaked its wiry neck and regarded Hazel and Frank, who were still lying unconscious.

“A male and female demigod,” said Lion Head. “These will do, if the others die.” Its hollow face mask turned back to Leo. “We do not need you, Leo Valdez.”

“Oh, hey!” Leo tried for a winning smile. “You always need Leo Valdez!”

He spread his hands and hoped he looked confident and useful, not desperate and terrified. He wondered if it was too late to write TEAM LEO on his shirt.

Sadly, the suits of armor were not as easily swayed as the Narcissus Fan Club had been.

The one with the wolf-headed helmet snarled, “I have been in your mind, Leo. I helped you start the war.”

Leo’s smile crumbled. He took a step back. “That was you?”

Now he understood why those tourists had bothered him right away, and why this thing’s voice sounded so familiar. He’d heard it in his mind.

“You made me fire the ballista?” Leo demanded. “You call that helping?”

“I know how you think,” said Wolf Head. “I know your limits. You are small and alone. You need friends to protect you. Without them, you are unable to withstand me. I vowed not to possess you again, but I can still kill you.”

The armored dudes stepped forward. The points of their swords hovered a few inches from Leo’s face.

Leo’s fear suddenly made way for a whole lot of anger. This eidolon in the wolf helmet had shamed him, controlled him, and made him attack New Rome. It had endangered his friends and botched their quest.

Leo glanced at the dormant spheres on the worktables. He considered his tool belt. He thought about the loft behind him—the area that looked like a sound booth. Presto: Operation Junk Pile was born.

“First: you don’t know me,” he told Wolf Head. “And second: Bye.”

He lunged for the stairs and bounded to the top. The suits of armor were scary, but they were not fast. As Leo suspected, the loft had doors on either side—folding metal gates. The operators would’ve wanted protection in case their creations went haywire…like now. Leo slammed both gates shut and summoned fire to his hands, fusing the locks.

The suits of armor closed in on either side. They rattled the gates, hacking at them with their swords.

“This is foolish,” said Lion Head. “You only delay your death.”

“Delaying death is one of my favorite hobbies.” Leo scanned his new home. Overlooking the workshop was a single table like a control board. It was crowded with junk, but most of it Leo dismissed immediately: a diagram for a human catapult that would never work; a strange black sword (Leo was no good with swords); a large bronze mirror (Leo’s reflection looked terrible); and a set of tools that someone had broken, either in frustration or clumsiness.

He focused on the main project. In the center of the table, someone had disassembled an Archimedes sphere. Gears, springs, levers, and rods were littered around it. All the bronze cables to the room below were connected to a metal plate under the sphere. Leo could sense the Celestial bronze running through the workshop like arteries from a heart—ready to conduct magical energy from this spot.

“One basketball to rule them all,” Leo muttered.

This sphere was a master regulator. He was standing at Ancient Roman mission control.

“Leo Valdez!” the spirit howled. “Open this gate or I will kill you!”

“A fair and generous offer!” Leo said, his eyes still on the sphere. “Just let me finish this. A last request, all right?”

That must have confused the spirits, because they momentarily stopped hacking at the bars.

Leo’s hands flew over the sphere, reassembling its missing pieces. Why did the stupid Romans have to take apart such a beautiful machine? They had killed Archimedes, stolen his stuff, then messed with a piece of equipment they could never understand. On the other hand, at least they’d had the sense to lock it away for two thousand years so that Leo could retrieve it.

The eidolons started pounding on the gates again.

“Who is it?” Leo called.

“Valdez!” Wolf Head bellowed.

“Valdez who?” Leo asked.

Eventually the eidolons would realize they couldn’t get in. Then, if Wolf Head truly knew Leo’s mind, he would decide there were other ways to force his cooperation. Leo had to work faster.

He connected the gears, got one wrong, and had to start again. Hephaestus’s Hand Grenades, this was hard!

Finally he got the last spring in place. The ham-fisted Romans had almost ruined the tension adjuster, but Leo pulled a set of watchmaker’s tools from his belt and did some final calibrations. Archimedes was a genius—assuming this thing actually worked.

He wound the starter coil. The gears began to turn. Leo closed the top of the sphere and studied its concentric circles—similar to the ones on the workshop door.

“Valdez!” Wolf Head pounded on the gate. “Our third comrade will kill your friends!”

Leo cursed under his breath. Our third comrade. He glanced down at the spindly-legged Taser ball that had knocked out Hazel and Frank. He had figured eidolon number three was hiding inside that thing. But Leo still had to deduce the right sequence to activate this control sphere.

“Yeah, okay,” he called. “You got me. Just…just a sec.”

“No more seconds!” Wolf Head shouted. “Open this gate now, or they die.”

The possessed Taser ball lashed out with its tendrils and sent another shock through Hazel and Frank. Their unconscious bodies flinched. That kind of electricity might have stopped their hearts.

Leo held back tears. This was too hard. He couldn’t do it.

He stared at the face of the sphere—seven rings, each one covered with tiny Greek letters, numbers, and zodiac signs. The answer wouldn’t be pi. Archimedes would never do the same thing twice. Besides, just by putting his hand on the sphere Leo could feel that the sequence had been generated randomly. It was something only Archimedes would know.

Supposedly, Archimedes’s last words had been: Don’t disturb my circles.

No one knew what that meant, but Leo could apply it to this sphere. The lock was much too complicated. Maybe if Leo had a few years, he could decipher the markings and figure out the right combination, but he didn’t even have a few seconds.

He was out of time. Out of luck. And his friends were going to die.

A problem you cannot solve, said a voice in his mind.

Nemesis…she’d told him to expect this moment. Leo thrust his hand in his pocket and brought out the fortune cookie. The goddess had warned him of a great price for her help—as great as losing an eye. But if he didn’t try, his friends would die.

“I need the access code for this sphere,” he said.

He broke open the cookie.

Chapter 40

Leo unfurled the little strip of paper. It read:

THAT’S YOUR REQUEST? SERIOUSLY? (OVER)

On the back, the paper said:

YOUR LUCKY NUMBERS ARE: TWELVE, JUPITER, ORION, DELTA, THREE, THETA, OMEGA. (WREAK VENGEANCE UPON GAEA, LEO VALDEZ.)

With trembling fingers, Leo turned the rings.

Outside the gates, Wolf Head growled in frustration. “If friends do not matter to you, perhaps you need more incentive. Perhaps I should destroy these scrolls instead—priceless works by Archimedes!”

The last ring clicked into place. The sphere hummed with power. Leo ran his hands along the surface, sensing tiny buttons and levers awaiting his commands.

Magical and electrical pulses coursed via the Celestial bronze cables, and surged through the entire room.

Leo had never played a musical instrument, but he imagined it must be like this—knowing each key or note so well that you didn’t really think about what your hands were doing. You just concentrated on the kind of sound you wanted to create.