“Are we winning?” I asked.

A Germanus screamed as Sherman Yang, head counselor of Ares cabin, threw him off the side of the building.

“Hard to tell,” Kayla said. “Chiron told the newbies this was a field trip. Like a training exercise. They gotta learn sooner or later.”

I scanned the terrace. Many of those first-time campers, some no older than eleven or twelve, were fighting wide-eyed alongside their cabinmates, trying to imitate whatever their counselors were doing. They seemed so very young, but then again, they were demigods. They’d probably already survived numerous terrifying events in their short lives. And Kayla was right—adventures would not wait for them to be ready. They had to jump in, sooner better than later.

“Rosamie!” Chiron called. “Sword higher, dear!”

The young girl grinned and lifted her blade, intercepting the strike of a security guard’s baton. She smacked her foe across the face with the flat of her blade. “Do we have field trips every week? This is cool!”

Chiron gave her a pained smile, then continued shooting down enemies.

Kayla bandaged my face as best she could—wrapping white gauze around my nose and making me go cross-eyed. I imagined I looked like the Partially Invisible Man, which made me giggle again.

Kayla grimaced. “Okay, we gotta clear your head. Drink this.” She lifted a vial to my lips.

“Nectar?”

“Definitely not nectar.”

The taste exploded in my mouth. Immediately, I realized what she was giving me and why: Mountain Dew, the glowing-lime-green elixir of perfect sobriety. I don’t know what effect it has on mortals, but ask any supernatural entity and they will tell you, Mountain Dew’s combination of sweetness, caffeine, and otherworldly je-ne-sais-quoi-peut-être-radioactif taste is enough to bring complete focus and seriousness to any god. My eyesight cleared. My giddiness evaporated. I had zero desire to giggle. A grim sense of danger and impending death gripped my heart. Mountain Dew is the equivalent of the enslaved servant who would ride behind the emperor during his triumphal parades, whispering, Remember, you are mortal, and you will die to keep him from getting a big head.

“Meg,” I said, recalling what was most important. “I need to find Meg.”

Kayla nodded grimly. “Then that’s what we’ll do. I brought you some extra arrows. Thought you might need them.”

“You are the most thoughtful daughter ever.”

She blushed right down to the red roots of her hair. “Can you walk? Let’s get moving.”

We ran inside and turned down a corridor that Kayla thought might lead to the stairwell. We pushed through another set of doors and found ourselves in the Dining Room of Disaster.

Under different circumstances, it might have been a lovely place for a dinner party: a table big enough for twenty guests, a Tiffany chandelier, a huge marble fireplace, and wood-paneled walls with niches for marble busts—each depicting the face of the same Roman emperor. (If you guessed Nero, you win a Mountain Dew.)

Not part of the dinner plans: a red forest bull had somehow found its way into the room and was now chasing a group of young demigods around the table while they yelled insults and pelted it with Nero’s golden plates, cups, and cutlery. The bull didn’t seem to realize it could simply smash through the dining table and trample the demigods, but I suspected it would eventually figure that out.

“Ugh, these things,” said Kayla when she saw the bull.

I thought this would make an excellent description in the camp’s encyclopedia of monsters. Ugh, these things was really all you needed to know about tauri silvestres.

“They can’t be killed,” I warned as we joined the other demigods in their game of ring-around-the-dining-table.

“Yeah, I know.” Kayla’s tone told me she’d already had a crash course in forest bulls during her field-trip fun. “Hey, guys,” she said to her young comrades. “We need to lure this thing outside. If we can trick it off the edge of the terrace—”

At the opposite end of room, the doors burst open. My son Austin appeared, his tenor sax at the ready. Finding himself right next to the bull’s head, he yelped, “Whoa!” then let loose a dissonant squeak-blatt on the sax that would have made Coltrane proud. The bull lurched away, shaking its head in dismay, as Austin vaulted over the dining table and slid to our side.

“Hey, guys,” he said. “We having fun yet?”

“Austin,” Kayla said with relief. “I need to lure this bull outside. Can you—?” She pointed at me.

“We playing pass-the-Apollo?” Austin grinned. “Sure. C’mon, Dad. I got you.”

As Kayla mustered the younger demigods and began shooting arrows to goad the bull into following her, Austin hustled me through a side door.

“Where to, Dad?” He politely did not ask why my nose was bandaged or why my breath smelled of Mountain Dew.

“I have to find Meg,” I said. “Three stories up? Southeast corner?”

Austin kept jogging with me down the corridor, but his mouth tightened in a thoughtful frown. “I don’t think anybody’s managed to fight their way up to that level yet, but let’s do it.”

We found a grand circular stairwell that took us up one more floor. We navigated a maze of corridors, then shouldered through a narrow door into the Hat Room of Horrors.

Troglodytes had found the mother lode of haberdashery. The oversize walk-in closet must have served as Nero’s seasonal coat-check area, because fall and winter jackets lined the walls. Shelves overflowed with scarves, gloves, and, yes, every conceivable manner of hat and cap. The trogs rifled through the collection with glee, stacking hats six or seven high on their heads, trying on scarves and galoshes to augment their incredibly civilized fashion sense.

One trog looked up at me through his dark goggles, cords of drool hanging from his lips. “Haaats!”

I could only smile and nod and creep carefully around the edge of the closet, hoping none of the trogs mistook us for chapeau poachers.

Thankfully, the trogs paid us no mind. We emerged from the other side of the closet into a marble foyer with a bank of elevators.

My hopes rose. Assuming this was the main entrance to Nero’s residential levels, where his most favored guests would be received, we were getting closer to Meg.

Austin stopped in front of a keypad with a golden inlaid SPQR symbol. “Looks like this elevator gives you direct access to the imperial apartments. But we’d need a key card.”

“Stairs?” I asked.

“I don’t know,” he said. “This close to the emperor’s quarters, I bet any passage up will be locked and booby-trapped. The Hermes cabin swept the lower stairwells, but I doubt they’ve made it this far. We’re the first.” He fingered the pads of his saxophone. “Maybe I could open the elevator with the right sequence of tones…?”

His voice trailed off as the elevator doors opened by themselves.

Inside stood a young demigod with disheveled blond hair and rumpled street clothes. Two golden rings gleamed on his middle fingers.

Cassius’s eyes widened when he saw me. Clearly, he hadn’t been expecting to run into me ever again. He looked like his last twenty-four hours had been almost as bad as mine. His face was gray, his eyes swollen and red from crying. He seemed to have developed a nervous twitch that traveled randomly around his body.