“Apollo,” Calypso hissed. “What are you doing?”

Lityerses answered for me. “He’s being smart. Now, where’s the third member of your little party?”

I blinked. “It—it’s just the two of us.”

Lityerses’s facial scars rippled, white lines on tan skin, like the ridges of a sand dune. “Come now. You flew into the city on a dragon. Three passengers. I very much want to see Leo Valdez again. We have unfinished business.”

“You know Leo?” Despite the danger we were in, I felt a small sense of relief. Finally, some villain wanted to kill Leo more than he wanted to kill me. That was progress!

Calypso didn’t seem so happy. She stepped toward the swordsman with her fists clenched. “What do you want with Leo?”

Lityerses narrowed his eyes. “You’re not the same girl who was with him before. Her name was Piper. You wouldn’t happen to be Leo’s girlfriend?”

Red blotches appeared on Calypso’s cheeks and neck.

Lityerses brightened. “Oh, you are! That’s wonderful! I can use you to hurt him.”

Calypso snarled. “You will not hurt him.”

Above Lityerses, the canopy roof shook again, as if a thousand rats were scurrying through the rafters. The vines seemed to be growing, the foliage turning thicker and darker.

“Calypso,” I said, “step back.”

“Why should I?” she demanded. “This Cornhusker just threatened—”

“Calypso!” I grabbed her wrist and yanked her from the shadow of the canopy just as it collapsed on top of Lityerses. The swordsman disappeared under hundreds of pounds of shingles, lumber, and ivy.

I surveyed the mass of quivering vines. I saw no orangutans, no gods, no one who might have been responsible for the collapse.

“She must be here,” I muttered.

“Who?” Calypso stared at me with wide eyes. “What just happened?”

I wanted to hope. I was afraid to hope. Whatever the case, we couldn’t stay. Lityerses was shouting and struggling under the wreckage, which meant he wasn’t dead. His Germani would be here any second.

“Let’s get out of here.” I pointed to the green locomotive. “I’m driving.”

Drivin’ the green train

I’m all like, Choo-choo! Choo-choo!

Can’t catch me!—Oh, poop!

A SLOW-MOTION GETAWAY was not what I had in mind.

We both jumped onto the conductor’s bench, which was barely wide enough for one, and jostled for space while punching pedals and turning random levers.

“I told you, I’ll drive!” I yelled. “If I can drive the sun, I can drive this!”

“This isn’t the sun!” Calypso elbowed me in the ribs. “It’s a model train.”

I found the ignition switch. The train lurched into motion. (Calypso will claim she found the ignition switch. This is a blatant lie.) I pushed Calypso off the bench and onto the ground. Since the train was only going half a mile an hour, she simply stood up, brushed off her skirt, and walked alongside me, glaring.

“That’s top speed?” she demanded. “Push some more levers!”

Behind us, from somewhere under the wreckage of the canopy, came a mighty “BLARG!” Ivy shivered as Lityerses tried to bust his way out.

A half dozen Germani appeared at the far end of the platform. (Commodus was definitely buying his barbarians by the imperial family-size pack.) The bodyguards stared at the screaming mass of roof wreckage, then at us choo-chooing away. Rather than give chase, they began clearing the beams and vines to free their boss. Given the progress we were making, they probably assumed they’d have plenty of time to come after us.

Calypso hopped onto the running board. She pointed to the controls. “Try the blue pedal.”

“The blue pedal is never the right one!”

She kicked it with her foot. We shot forward at three times our previous speed, which meant our enemies would now have to jog at a moderate pace to catch us.

The track curved as we continued to accelerate, our wheels squealing against the outer rail. The station disappeared behind a line of trees. On our left, the terrain opened up, revealing the majestic butts of African elephants who were picking through a pile of hay. Their zookeeper frowned as we trundled past. “Hey!” he yelled. “Hey!”

I waved. “Morning!”

Then we were gone. The cars shook dangerously as we picked up steam. My teeth clattered. My bladder sloshed. Up ahead, almost hidden behind a screen of bamboo, a fork in the track was marked by a sign in Latin: BONUM EFFERCIO.

“There!” I yelled. “The Good Stuff! We need to turn left!”

Calypso squinted at the console. “How?”

“There should be a switch,” I said. “Something that operates the turnout.”

Then I saw it—not on our console, but ahead of us on the side of the tracks—an old-fashioned hand lever. There was no time to stop the train, no time to run ahead and turn the switch by hand.

“Calypso, hold this!” I tossed her the Tots and unslung my bow. I nocked an arrow.

Once, such a shot would’ve been child’s play for me. Now it was nearly impossible: shooting from a moving train, aiming for a point where the focused impact of an arrow would have the maximum chance of triggering the switch.

I thought of my daughter Kayla back at Camp Half-Blood. I imagined her calm voice as she coached me through the frustrations of mortal archery. I remembered the other campers’ encouragement the day on the beach when I’d made a shot that brought down the Colossus of Nero.

I fired. The arrow slammed into the lever and forced it backward. The point blades shifted. We lurched onto the spur line.

“Down!” Calypso yelled.

We crashed through bamboo and careened into a tunnel just wide enough for the train. Unfortunately, we were going much too fast. The choo-choo tilted sideways, throwing sparks off the wall. By the time we shot out the other side of the tunnel, we were completely off-balance.

The train groaned and tilted—a sensation I knew well from those times the sun chariot had to veer to avoid a launching space shuttle or a Chinese celestial dragon. (Those things are annoying.)

“Out!” I tackled Calypso—yes, again—and leaped from the right side of the train as the line of cars spilled to the left, toppling off the tracks with a sound like a bronze-clad army being crushed by a giant fist. (I may have crushed a few armies that way back in the old days.)

The next thing I knew I was on all fours, my ear pressed against the ground as if listening for a herd of buffalo, though I had no idea why.

“Apollo.” Calypso tugged at the sleeve of my coat. “Get up.”

My throbbing head felt several times larger than usual, but I didn’t seem to have broken any bones. Calypso’s hair had come loose around her shoulders. Her silver parka was dusted with sand and bits of gravel. Otherwise she looked intact. Perhaps our formerly divine constitutions had saved us from damage. Either that or we were just lucky.

We had crashed in the middle of a circular arena. The train lay curled sideways across the gravel like a dead caterpillar, a few feet shy of where the tracks ended. The perimeter was ringed with animal enclosures—Plexiglas walls framed in stone. Above that rose three tiers of stadium seating. Over the top of the amphitheater stretched a canopy of camouflage netting like I’d seen at the orangutan habitat—though here I suspected the netting was meant to keep winged monsters from flying away.