“Caligae,” Piper said. “Like Caligula.”

“Exactly,” I agreed. “These are the adult version of the little booties that gave Gaius Julius Caesar Germanicus his childhood nickname.”

Piper wrinkled her nose. “Can you sense any magic?”

“Well, they’re not buzzing with energy,” I said. “Or giving me flashbacks of stinky feet, or compelling me to put them on. But I think they’re the right shoes. These are his namesake. They carry his power.”

“Hmm. I suppose if you can talk to an arrow, you can read a pair of sandals.”

“It’s a gift,” I agreed.

She knelt next to me and took one of the sandals. “This won’t fit me. Way too big. They look about your size.”

“Are you implying I have big feet?”

Her smile flickered. “These look almost as uncomfortable as the shoes of shame—this horrible white pair of nurse’s shoes we had back in the Aphrodite cabin. You’d have to wear them as punishment if you did something bad.”

“That sounds like Aphrodite.”

“I got rid of them,” she said. “But these…I suppose as long as you don’t mind putting your feet where Caligula’s feet have been—”

“DANGER!” cried a voice behind us.

Sneaking up behind someone and yelling danger is an excellent way to make them simultaneously leap, spin, and fall on their butts, which is what Piper and I did.

In the doorway stood Crest, his white fur matted and dripping as if he’d flown through Caligula’s swimming pool. His eight-fingered hands wrapped around the door frame on either side. His chest heaved. His black suit was torn to pieces.

“Strixes,” he panted.

My heart leaped into my nasal cavity. “Are they following you?”

He shook his head, his ears rippling like startled squids. “I think I evaded them, but—”

“Why are you here?” Piper demanded, her hand going to her dagger.

The look in Crest’s eyes was a mixture of panic and hunger. He pointed to my ukulele. “You can show me how to play?”

“I…yes,” I said. “Though a guitar might be better, given the size of your hands.”

“That chord,” he said. “The one that made Wah-Wah screech. I want it.”

I rose slowly, so as not to startle him further. “Knowledge of the C minor 6 tri-chord is an awesome responsibility. But, yes, I could show you.”

“And you.” He looked at Piper. “The way you sing. Can you teach me?”

Piper’s hand dropped from her hilt. “I—I guess I could try, but—”

“Then we must leave now!” Crest said. “They have already captured your friends!”

“What?” Piper got to her feet. “Are you sure?”

“The scary girl. The lightning boy. Yes.”

I swallowed back my despair. Crest had given a flawless description of Meg and Jason. “Where?” I asked. “Who has them?”

“Him,” Crest said. “The emperor. His people will be here soon. We must fly! Be the musicians in the world!”

Under different circumstances, I would have considered this excellent advice, but not with our friends captured. I wrapped up the emperor’s sandals and stuffed them into the bottom of my quiver. “Can you take us to our friends?”

“No!” Crest wailed. “You will die! The sorceress—”

Why did Crest not hear the enemies sneaking up behind him? I don’t know. Perhaps Jason’s lightning had left a ringing in his ears. Perhaps he was too distressed, too focused on us to guard his own back.

Whatever the case, Crest hurtled forward, crashing face-first into the box with the winged sandals. He collapsed on the carpet, the freed flying shoes kicking him repeatedly about the head. On his back glistened two deep impressions in the shape of horse hooves.

In the doorway stood a majestic white stallion, his head just clearing the top of the frame. In a flash, I realized why the emperor’s yachts had such tall ceilings, wide hallways and doorways: they were designed to accommodate this horse.

“Incitatus,” I said.

He locked eyes with me as no horse should be able to do—his huge brown pupils glinting with malicious awareness. “Apollo.”

Piper looked stunned, as one does when encountering a talking horse on a shoe yacht.

She began to say, “What the—?”

Incitatus charged. He trampled straight over the coffee table and head-butted Piper against the wall with a sickening crunch. Piper dropped to the carpet.

I rushed toward her, but the horse slammed me away. I landed on the nearest sofa.

“Well, now.” Incitatus surveyed the damage—the overturned pedestals and destroyed coffee table; broken bottles of exotic spring water seeping into the carpet; Crest groaning on the floor, the flying shoes still kicking him; Piper unmoving, blood trickling from her nose; and me on the sofa, cradling my bruised ribs.

“Sorry to intrude on your intrusion,” he said. “I had to knock the girl out quickly, you understand. I don’t like charmspeak.”

His voice was the same as I’d heard while hiding in the dumpster behind Macro’s Military Madness—deep and world-weary, tinged with annoyance, as if he’d seen every possible stupid thing bipeds could do.

I stared in horror at Piper McLean. She didn’t appear to be breathing. I remembered the words of the Sibyl…especially that terrible word that began with D.

“You—you killed her,” I stammered.

“Did I?” Incitatus nuzzled Piper’s chest. “Nah. Not yet, but soon enough. Now come along. The emperor wants to see you.”

SOME of my best friends are magic horses.

Arion, the swiftest steed in the world, is my cousin, though he rarely comes to family dinners. The famous winged Pegasus is also a cousin—once removed, I think, since his mother was a gorgon. I’m not sure how that works. And, of course, the sun horses were my favorite steeds—though, thankfully, none of them talked.

Incitatus, however?

I didn’t like him much.

He was a beautiful animal—tall and muscular, his coat gleaming like a sunlit cloud. His silky white tail swished behind him as if daring any flies, demigods, or other pests to approach his hindquarters. He wore neither tack nor saddle, though golden horseshoes gleamed on his hooves.

His very majesty grated on me. His jaded voice made me feel small and unimportant. But what I really hated were his eyes. Horse eyes should not be so cold and intelligent.

“Climb on,” he said. “My boy is waiting.”

“Your boy?”

He bared his marble-white teeth. “You know who I mean. Big C. Caligula. The New Sun who’s gonna eat you for breakfast.”

I sank deeper into the sofa cushions. My heart pounded. I had seen how fast Incitatus could move. I didn’t like my chances against him alone. I would never be able to fire an arrow or strum a tune before he kicked my face in.

This would have been an excellent time for a surge of godly strength, so I could throw the horse out the window. Alas, I felt no such energy within me.

Nor could I expect any backup. Piper groaned, twitching her fingers. She looked half-conscious at best. Crest whimpered and tried to curl into a ball to escape the bullying of the winged shoes.