The Mark of Athena (The Heroes of Olympus #3)(114)

Leo listened to the Spanish tour guide for a few seconds, and then he reported to his friends, “This is the Pantheon. It was originally built by Marcus Agrippa as a temple to the gods. After it burned down, Emperor Hadrian rebuilt it, and it’s been standing for two thousand years. It’s one of the best-preserved Roman buildings in the world.”

Frank and Hazel stared at him.

“How did you know that?” Hazel asked.

“I’m naturally brilliant.”

“Centaur poop,” Frank said. “He eavesdropped on a tour group.”

Leo grinned. “Maybe. Come on. Let’s go find that secret passage. I hope this place has air conditioning.”

Of course, no AC.

On the bright side, there were no lines and no admission fee, so they just muscled their way past the tour groups and walked on in.

The interior was pretty impressive, considering it had been constructed two thousand years ago. The marble floor was patterned with squares and circles like a Roman tic-tac-toe game. The main space was one huge chamber with a circular rotunda, sort of like a capitol building back in the States. Lining the walls were different shrines and statues and tombs and stuff. But the real eye-catcher was the dome overhead. All the light in the building came from one circular opening right at the top. A beam of sunlight slanted into the rotunda and glowed on the floor, like Zeus was up there with a magnifying glass, trying to fry puny humans.

Leo was no architect like Annabeth, but he could appreciate the engineering. The Romans had made the dome out of big stone panels, but they’d hollowed out each panel in a square-within-square pattern. It looked cool. Leo figured it also made the dome lighter and easier to support.

He didn’t mention that to his friends. He doubted they would care, but if Annabeth were here, she would’ve spent the whole day talking about it. Thinking about that made Leo wonder how she was doing on her Mark of Athena expedition. Leo never thought he’d feel this way, but he was worried about that scary blond girl.

Hazel stopped in the middle of the room and turned in a circle. “This is amazing. In the old days, the children of Vulcan would come here in secret to consecrate demigod weapons. This is where Imperial gold was enchanted.”

Leo wondered how that worked. He imagined a bunch of demigods in dark robes trying to quietly roll a scorpion ballista through the front doors.

“But we’re not here because of that,” he guessed.

“No,” Hazel said. “There’s an entrance—a tunnel that will lead us toward Nico. I can sense it close by. I’m not sure where.”

Frank grunted. “If this building is two thousand years old, it makes sense there could be some kind of secret passage left over from the Roman days.”

That’s when Leo made his mistake of simply being too good.

He scanned the temple’s interior, thinking: If I were designing a secret passage, where would I put it?

He could sometimes figure out how a machine worked by putting his hand on it. He’d learned to fly a helicopter that way. He’d fixed Festus the dragon that way (before Festus crashed and burned). Once he’d even reprogrammed the electronic billboards in Times Square to read: ALL DA LADIES LUV LEO…accidentally, of course.

Now he tried to sense the workings of this ancient building. He turned toward a red marble altar-looking thing with a statue of the Virgin Mary on the top. “Over there,” he said.

He marched confidently to the shrine. It was shaped sort of like a fireplace, with an arched recess at the bottom. The mantel was inscribed with a name, like a tomb.

“The passage is around here,” he said. “This guy’s final resting place is in the way. Raphael somebody?”

“Famous painter, I think,” Hazel said.

Leo shrugged. He had a cousin named Raphael, and he didn’t think much of the name. He wondered if he could produce a stick of dy***ite from his tool belt and do a little discreet demolition; but he figured the caretakers of this place probably wouldn’t approve.

“Hold on…” Leo looked around to make sure they weren’t being watched.

Most of the tour groups were gawking at the dome, but one trio made Leo uneasy. About fifty feet away, some overweight middle-aged dudes with American accents were conversing loudly, complaining to each other about the heat. They looked like manatees stuffed into beach clothes—sandals, walking shorts, touristy T-shirts and floppy hats. Their legs were big and pasty and covered with spider veins. The guys acted extremely bored, and Leo wondered why they were hanging around.

They weren’t watching him. Leo wasn’t sure why they made him nervous. Maybe he just didn’t like manatees.

Forget them, Leo told himself.

He slipped around the side of the tomb. He ran his hand down the back of a Roman column, all the way to the base. Right at the bottom, a series of lines had been etched into the marble—Roman numerals.

“Heh,” Leo said. “Not very elegant, but effective.”

“What is?” Frank asked.

“The combination for a lock.” He felt around the back of the column some more and discovered a square hole about the size of an electrical socket. “The lock face itself has been ripped out—probably vandalized sometime in the last few centuries. But I should be able to control the mechanism inside, if I can…”

Leo placed his hand on the marble floor. He could sense old bronze gears under the surface of the stone. Regular bronze would have corroded and become unusable long ago, but these were Celestial bronze—the handiwork of a demigod. With a little willpower, Leo urged them to move, using the Roman numerals to guide him. The cylinders turned—click, click, click. Then click, click.