“Anyway,” Rachel continued, “my theory is that Nero would keep his fasces here.” She tapped a point about halfway up the tower’s cross-section schematic. “Right in the middle of the building. It’s the only level with no exterior windows. Special-elevator access only. All doors are Celestial-bronze–reinforced. I mean, the whole building is a fortress, but this level would be impossible to break into.”

Meg nodded. “I know the floor you mean. We were never allowed in there. Ever.”

A chill settled over our little group. Goose bumps dotted Will’s arms. The idea of Meg, our Meg, stuck in that fortress of evil was more disturbing than any number of mysterious cows or penguins.

Rachel flipped to another blueprint—a floor plan of the ultra-secure level. “Here. This vault has to be it. You could never get close, unless…” She pointed to a nearby room. “If I’m reading these designs correctly, this would be a holding cell for prisoners.” Her eyes were bright with excitement. “If you could get yourself captured, then convince someone on the inside to help you escape—”

“Lu was right.” Meg looked at me triumphantly. “I told you.”

Rachel frowned, bringing the blue paint spots on her forehead into a tighter cluster. “Who is Lu?”

We told her about Luguselwa, and the special bonding time we’d shared before I threw her off a building.

Rachel shook her head. “Okay…so if you’ve already thought of all my ideas, why am I even talking?”

“No, no,” Will said. “You’re confirming. And we trust you more than…er, other sources.”

I hoped he meant Lu and not me.

“Besides,” Nico said, “you have actual blueprints.” He studied the floor plan. “Why would Nero keep his prisoners on the same level as his most valuable possession, though?”

“Keep your fasces close,” I speculated, “and your enemies closer.”

“Maybe,” Rachel said. “But the fasces is heavily protected, and not just by security features or regular guards. There’s something in that vault, something alive.…”

It was my turn to get goose bumps. “How do you know this?”

“A vision. Just a glimpse, almost like…like Python wanted me to see it. The figure looked like a man, but his head—”

“A lion’s head,” I guessed.

Rachel flinched. “Exactly. And slithering around his body—”

“Snakes.”

“So you know what it is?”

I grasped for the memory. As usual, it was just out of reach. You may wonder why I didn’t have a better handle on my godly knowledge, but my mortal brain was an imperfect storage facility. I can only compare my frustration to how you might feel when taking a picky reading-comprehension quiz. You are assigned fifty pages. You actually read them. Then the teacher decides to test you by asking, Quick! What was the first word on page thirty-seven?

“I’m not sure,” I admitted. “Some sort of powerful guardian, obviously. Our most recent prophecy stanza mentioned a lion, snake-entwined.” I filled Rachel in on our literally eye-popping ride with the Gray Sisters.

Nico scowled at the blueprints, as if he might intimidate them into giving up their secrets. “So, whatever the guardian is, Nero trusts it with his life. Meg, I thought you said Luguselwa was this huge, mighty warrior?”

“She is.”

“So why can’t she take out this guardian and destroy the fasces herself?” he asked. “Why does she need…you know, you guys to get yourself captured?”

Nico phrased the question diplomatically, but I heard what he meant. If Lu couldn’t take out this guardian, how could I, Lester Papadopoulos, the Not So Huge or Mighty?

“Dunno,” Meg said. “But there must be a reason.”

Like Lu would rather see us get killed, I thought, but I knew better than to say that.

“Let’s assume Lu is right,” Nico said. “You get captured and put in this cell. She lets you out. You kill the guardian, destroy the fasces, weaken Nero, hooray. Even then, and I’m sorry to be a Debbie Downer—”

“I am calling you Debbie Downer from now on,” Will said gleefully.

“Shut up, Solace. Even then, you’ve got half a tower and Nero’s whole army of security guards between you and his throne room, right?”

“We’ve dealt with whole armies before,” Meg said.

Nico laughed, which I didn’t know he was capable of. “Okay. I like the confidence. But wasn’t there that little detail about Nero’s panic switch? If he feels threatened, he can blow up New York at the push of a button. How do you stop that?”

“Oh…” Rachel muttered a curse not appropriate for priestesses. “That must be what these are for.”

Her hands trembling, she flipped to another page of the blueprints.

“I asked my dad’s senior architect about them,” she said. “He couldn’t figure them out. Said there’s no way the blueprints could be right. Sixty feet underground, surrounded by triple retaining walls. Giant vats, like the building has its own reservoir or water-treatment facility. It’s connected to the city’s sewer mains, but the separate electrical grid, the generators, these pumps…It’s like the whole system is designed to blast water outward and flood the city.”

“Except not with water,” Will said. “With Greek fire.”

“Debbie Downer,” Nico muttered.

I stared at the schematics, trying to imagine how such a system could have been built. During our last battle in the Bay Area, Meg and I had seen more Greek fire than had existed in the whole history of the Byzantine Empire. Nero had more. Exponentially more. It seemed impossible, but the emperor had had hundreds of years to plan, and almost infinite resources. Leave it to Nero to spend most of his money on a self-destruct system.

“He’ll burn up, too,” I marveled. “All his family and guards, and his precious tower.”

“Maybe not,” Rachel said. “The building is designed for self-containment. Thermal insulation, closed air circulation, reinforced heat-resistant materials. Even the windows are special blast-proof panes. Nero could burn the city down around him, and his tower would be the only thing left standing.”

Meg crumpled her empty Yoo-hoo box. “Sounds like him.”

Will studied the plans. “I’m not an expert on reading these things, but where are the access points to the vats?”

“There’s only one,” Rachel said. “Sealed off, automated, heavily guarded, and under constant surveillance. Even if you could break or sneak through, you wouldn’t have enough time to disable the generators before Nero pushed his panic button.”

“Unless,” Nico said, “you tunneled your way into those reservoirs from underneath. You could sabotage his whole delivery system without Nero ever knowing.”

“Aaand we’re back to that terrible idea,” Will said.

“They’re the best tunnelers in the world,” Nico insisted. “They could get through all that concrete and steel and Celestial bronze with no one even noticing. This is our part of the plan, Will. While Apollo and Meg are getting themselves captured, keeping Nero distracted, we go underground and take out his doomsday weapon.”