“Oh, that’s very helpful. I mean, what is it?”

Then I heard heavy footsteps shaking the corridor—coming toward us.

“Run?” I asked.

“Run,” Rachel agreed.

We turned and fled the way we’d come, but we didn’t make it twenty feet before we ran straight into some old friends. Two dracaenae—snake women in Greek armor—leveled their javelins at our chests. Standing between them was Kelli, the empousa cheerleader.

“Well, well,” Kelli said.

I uncapped Riptide, and Annabeth pulled her knife; but before my sword was even out of pen form, Kelli pounced on Rachel. Her hand turned into a claw and she spun Rachel around, holding her tight with her talons at Rachel’s neck.

“Taking your little mortal pet for a walk?” Kelli asked me. “They’re such fragile things. So easy to break!”

Behind us, the footsteps came closer. A huge form appeared out of the gloom—an eight-foot-tall Laistrygonian giant with red eyes and fangs.

The giant licked his lips when he saw us. “Can I eat them?”

“No,” Kelli said. “Your master will want these. They will provide a great deal of entertainment.” She smiled at me. “Now march, half-bloods. Or you all die here, starting with the mortal girl.”

***

It was pretty much my worst nightmare. And believe me, I’ve had plenty of nightmares. We were marched down the tunnel, flanked by dracaenae, with Kelli and the giant in back, just in case we tried to run for it. Nobody seemed to worry about us running forward. That was the direction they wanted us to go.

Up ahead I could see bronze doors. They were about ten feet tall, emblazoned with a pair of crossed swords. From behind them came a muffled roar, like from a crowd.

“Oh, yessssss,” said the snake woman on my left. “You’ll be very popular with our hossssst.”

I’d never gotten to look at a dracaena up close before, and I wasn’t real thrilled to have the opportunity. She would’ve had a beautiful face, except her tongue was forked and her eyes were yellow with black slits for pupils. She wore bronze armor that stopped at her waist. Below that, where her legs should’ve been, were two massive snake trunks, mottled bronze and green. She moved by a combination of slithering and walking, as if she were on living skis.

“Who’s your host?” I asked.

She hissed, which might have been a laugh. “Oh, you’ll sssssee. You’ll get along furiousssly. He’ssss your brother, after all.”

“My what?” Immediately I thought of Tyson, but that was impossible. What was she talking about?

The giant pushed past us and opened the doors. He picked up Annabeth by her shirt and said, “You stay here.”

“Hey!” she protested, but the guy was twice her size and he’d already confiscated her knife and my sword.

Kelli laughed. She still had her claws at Rachel’s neck. “Go on, Percy. Entertain us. We’ll wait here with your friends to make sure you behave.”

I looked at Rachel. “I’m sorry. I’ll get you out of this.”

She nodded as much as she could with a demon at her throat. “That would be nice.”

The dracaenae prodded me toward the doorway at javelin-point, and I walked out onto the floor of an arena.

***

I guess it wasn’t the largest arena I’d ever been in, but it seemed pretty spacious considering the whole place was underground. The dirt floor was circular, just big enough that you could drive a car around the rim if you pulled it really tight. In the center of the arena, a fight was going on between a giant and a centaur. The centaur looked panicked. He was galloping around his enemy, using sword and shield, while the giant swing a javelin the size of a telephone pole and the crowd cheered.

The first tier of seats was twelve feet above the arena floor. Plain stone benches wrapped all the way around, and every seat was full. There were giants, dracaenae, demigods, telekhines, and stranger things: bat-winged demons and creatures that seemed half human and half you name it—bird, reptile, insect, mammal.

But the creepiest things were the skulls. The arena was full of them. They ringed the edge of the railing. Three-foot-high piles of them decorated the steps between the benches. They grinned from pikes at the back of the stands and hung on chains from the ceiling like horrible chandeliers. Some of them looked very old—nothing but bleached-white bone. Others looked a lot fresher. I’m not going to describe them. Believe me, you don’t want me to.

In the middle of all this, proudly displayed on the side of the spectator’s wall, was something that made no sense to me—a green banner with the trident of Poseidon in the center. What was that doing in a horrible place like this?

Above the banner, sitting in a seat of honor, was an old enemy.

“Luke,” I said.

I’m not sure he could hear me over the roar of the crowd, but he smiled coldly. He was wearing camouflage pants, a white T-shirt, and bronze breastplate, just like I’d seen in my dream. But he still wasn’t wearing his sword, which I thought was strange. Next to him sat the largest giant I’d ever seen, much larger than the one on the floor fighting the centaur. The giant next to Luke must’ve been fifteen feet tall, easy, and so wide he took up three seats. He wore only a loincloth, like a sumo wrestler. His skin was dark red and tattooed with blue wave designs. I figured he must be Luke’s new bodyguard or something.

There was a cry from the arena floor, and I jumped back as the centaur crashed to the dirt beside me.

He met my eyes pleadingly. “Help!”

I reached for my sword, but it had been taken from me and hadn’t reappeared in my pocket yet.

The centaur struggled to get up as the giant approached, his javelin ready.

A taloned hand gripped my shoulder. “If you value your friendsss’ livesss,” my dracaena guard said, “you won’t interfere. This isssn’t your fight. Wait your turn.”

The centaur couldn’t get up. One of his legs was broken. The giant put his huge foot on the horseman’s chest and raised the javelin. He looked up at Luke. The crowd cheered, “DEATH! DEATH!”

Luke didn’t do anything, but the tattooed sumo dude sitting next to him arose. He smiled down at the centaur, who was whimpering, “Please! No!”

Then the sumo dude held out his hand and gave the thumbs down sign.

I closed my eyes as the gladiator giant thrust his javelin. When I looked again, the centaur was gone, disintegrated to ashes. All that was left was a single hoof, which the giant took up as a trophy and showed the crowd. They roared their approval.

A gate opened at the opposite end of the stadium and the giant marched out in triumph.

In the stands, the sumo dude raised his hands for silence.

“Good entertainment!” he bellowed. “But nothing I haven’t seen before. What else do you have, Luke, Son of Hermes?”

Luke’s jaw tightened. I could tell he didn’t like being called son of Hermes. He hated his father. But he rose calmly to his feet. His eyes glittered. In fact, he seemed to be in a pretty good mood.

“Lord Antaeus,” Luke said, loud enough for the crowd to hear. “You have been an excellent host! We would be happy to amuse you, to repay the favor of passing through your territory.”

“A favor I have not yet granted,” Antaeus growled. “I want entertainment!”

Luke bowed. “I believe I have something better than centaurs to fight in your arena now. I have a brother of yours.” He pointed at me. “Percy Jackson, son of Poseidon.”

The crowd began jeering at me and throwing stones, most of which I dodged, but one caught me on the cheek and made a good-sized cut.

Antaeus’s eyes lit up. “A son of Poseidon? Then he should fight well! Or die well!”

“If his death pleases you,” Luke said, “will you let our armies cross your territory?”

“Perhaps!” Antaeus said.

Luke didn’t look too pleased about the “perhaps.” He glared down at me, as if warning me that I’d better die in a really spectacular way or I’d be in big trouble.

“Luke!” Annabeth yelled. “Stop this. Let us go!”

Luke seemed to notice her for the first time. He looked stunned for a moment. “Annabeth?”

“Enough time for the females to fight afterward,” Antaeus interrupted. “First, Percy Jackson, what weapons will you choose?”

The dracaenae pushed me into the middle of the arena.

I stared up at Antaeus. “How can you be a son of Poseidon?”

“I am his favorite son!” Antaeus boomed. “Behold, my temple to the Earthshaker, built from the skulls of all those I’ve killed in his name! Your skull shall join them!”

I stared in horror at all the skulls—hundreds of them—and the banner of Poseidon. How could this be a temple for my dad? My dad was a nice guy. He’d never ask me for a Father’s Day card, much less somebody’s skull.

“Percy!” Annabeth yelled at me. “His mother is Gaea! Gae—”

Her Laistrygonian captor clamped his hand over her mouth. His mother is Gaea. The earth goddess. Annabeth was trying to tell me that was important, but I didn’t know why. Maybe just because the guy had two godly parents. That would make him even harder to kill.

“You’re crazy, Antaeus,” I said. “If you think this is a good tribute, you know nothing about Poseidon.”

The crowd screamed insults at me, but Antaeus raised his hand for silence.

“Weapons,” he insisted. “And then we will see how you die. Will you have axes? Shields? Nets? Flamethrowers?”

“Just my sword,” I said.

Laughter erupted from the monsters, but immediately Riptide appeared in my hands, and some of the voices in the crowd turned nervous. The bronze blade glowed with a faint light.

“Round one!” Antaeus announced. The gates opened, and a dracaena slithered out. She had a trident in one hand and a weighted net in the other— classic gladiator style. I’d trained against those weapons at camp for years.

She jabbed at me experimentally. I stepped away. She threw her net, hoping to tangle my sword hand, but I sidestepped easily, sliced her spear in half, and stabbed Riptide through a chink in her armor. With a painful wail, she vaporized into nothing, and the cheering of the crowd died.

“No!” Antaeus bellowed. “Too fast! You must wait for the kill. Only I give that order!”

I glanced over at Annabeth and Rachel. I had to find a way to get them free, maybe distract their guards.

“Nice job, Percy.” Luke smiled. “You’ve gotten better with the sword. I’ll grant you that.”

“Round two!” Antaeus yelled. “And slower this time! More entertainment! Wait for my call before killing anybody. OR ELSE!”

The gates opened again, and this time a young warrior came out. He was a little older than me, about sixteen. He had glossy black hair, and his left eye was covered with an eye patch. He was thin and wiry so his Greek armor hung on him loosely. He stabbed his sword into the dirt, adjusted his shield straps, and pulled on his horsehair helmet.