I have no idea what the Miamians thought as we galloped by.

Streets and buildings began to blur as the centaurs picked up speed. It felt as if space were compacting—as if each centaur step took us miles and miles. In no time, we'd left the city behind. We raced through marshy fields of high grass and ponds and stunted trees.

Finally, we found ourselves in a trailer park at the edge of a lake. The trailers were all horse trailers, tricked out with televisions and mini-refrigerators and mosquito netting. We were in a centaur camp.

"Dude!" said a party pony as he unloaded his gear. "Did you see that bear guy? He was all like: 'Whoa, I have an arrow in my mouth! "

The centaur with the googly-eye glasses laughed. "That was awesome! Head slam!"

The two centaurs charged at each other full-force and knocked heads, then went staggering off in different directions with crazy grins on their faces.

Chiron sighed. He set Annabeth and Grover down on a picnic blanket next to me. "I really wish my cousins wouldn't slam their heads together. They don't have the brain cells to spare."

"Chiron," I said, still stunned by the fact that he was here. "You saved us."

He gave me a dry smile. "Well now, I couldn't very well let you die, especially since you've cleared my name."

"But how did you know where we were?" Annabeth asked.

"Advanced planning, my dear. I figured you would wash up near Miami if you made it out of the Sea of Monsters alive. Almost everything strange washes up near Miami."

"Gee, thanks," Grover mumbled.

"No, no," Chiron said. "I didn't mean… Oh, never mind. I am glad to see you, my young satyr. The point is, I was able to eavesdrop on Percy's Iris-message and trace the signal. Iris and I have been friends for centuries. I asked her to alert me to any important communications in this area. It then took no effort to convince my cousins to ride to your aid. As you see, centaurs can travel quite fast when we wish to. Distance for us is not the same as distance for humans."

I looked over at the campfire, where three party ponies were teaching Tyson to operate a paintball gun. I hoped they knew what they were getting into.

"So what now?" I asked Chiron. "We just let Luke sail away? He's got Kronos aboard that ship. Or parts of him, anyway."

Chiron knelt, carefully folding his front legs underneath him. He opened the medicine pouch on his belt and started to treat my wounds. "I'm afraid, Percy, that today has been something of a draw. We didn't have the strength of numbers to take that ship. Luke was not organized enough to pursue us. Nobody won."

"But we got the Fleece!" Annabeth said. "Clarisse is on her way back to camp with it right now."

Chiron nodded, though he still looked uneasy. "You are all true heroes. And as soon as we get Percy fixed up, you must return to Half-Blood Hill. The centaurs shall carry you."

"You're coming, too?" I asked.

"Oh yes, Percy. I'll be relieved to get home. My brethren here simply do not appreciate Dean Martin's music. Besides, I must have some words with Mr. D. There's the rest of the summer to plan. So much training to do. And I want to see… I'm curious about the Fleece."

I didn't know exactly what he meant, but it made me worried about what Luke had said: I was going to let you take the Fleece… once I was done with it.

Had he just been lying? I'd learned with Kronos there was usually a plan within a plan. The titan lord wasn't called the Crooked One for nothing. He had ways of getting people to do what he wanted without them ever realizing his true intentions.

Over by the campfire, Tyson let loose with his paintball gun. A blue projectile splattered against one of the centaurs, hurling him backward into the lake. The centaur came up grinning, covered in swamp muck and blue paint, and gave Tyson two thumbs up.

"Annabeth," Chiron said, "perhaps you and Grover would go supervise Tyson and my cousins before they, ah, teach each other too many bad habits?"

Annabeth met his eyes. Some kind of understanding passed between them.

"Sure, Chiron," Annabeth said. "Come on, goat boy."

"But I don't like paintball."

"Yes, you do." She hoisted Grover to his hooves and led him off toward the campfire.

Chiron finished bandaging my leg. "Percy, I had a talk with Annabeth on the way here. A talk about the prophecy."

Uh-oh, I thought.

"It wasn't her fault," I said. "I made her tell me."

His eyes flickered with irritation. I was sure he was going to chew me out, but then his look turned to weariness. "I suppose I could not expect to keep it secret forever."

"So am I the one in the prophecy?"

Chiron tucked his bandages back into his pouch. "I wish I knew, Percy. You're not yet sixteen. For now we must simply train you as best we can, and leave the future to the Fates."

The Fates. I hadn't thought about those old ladies in a long time, but as soon as Chiron mentioned them, something clicked.

"That's what it meant," I said.

Chiron frowned. "That's what what meant?"

"Last summer. The omen from the Fates, when I saw them snip somebody's life string. I thought it meant I was going to die right away, but it's worse than that. It's got something to do with your prophecy. The death they foretold—it's going to happen when I'm sixteen."

Chiron's tail whisked nervously in the grass. "My boy, you can't be sure of that. We don't even know if the prophecy is about you."

"But there isn't any other half-blood child of the Big Three!"

"That we know of."

"And Kronos is rising. He's going to destroy Mount Olympus!"

"He will try," Chiron agreed. "And Western Civilization along with it, if we don't stop him. But we will stop him. You will not be alone in that fight."

I knew he was trying to make me feel better, but I remembered what Annabeth had told me. It would come down to one hero. One decision that would save or destroy the West. And I felt sure the Fates had been giving me some kind of warning about that. Something terrible was going to happen, either to me or to somebody I was close to.

"I'm just a kid, Chiron," I said miserably. "What good is one lousy hero against something like Kronos?"

Chiron managed a smile. "What good is one lousy hero'? Joshua Lawrence Chamberlain said something like that to me once, just before he single-handedly changed the course of your Civil War."

He pulled an arrow from his quiver and turned the razor-sharp tip so it glinted in the firelight. "Celestial bronze, Percy. An immortal weapon. What would happen if you shot this at a human?"

"Nothing," I said. "It would pass right through."

"That's right," he said. "Humans don't exist on the same level as the immortals. They can't even be hurt by our weapons. But you, Percy—you are part god, part human. You live in both worlds. You can be harmed by both, and you can affect both. That's what makes heroes so special. You carry the hopes of humanity into the realm of the eternal. Monsters never die. They are reborn from the chaos and barbarism that is always bubbling underneath civilization, the very stuff that makes Kronos stronger. They must be defeated again and again, kept at bay. Heroes embody that struggle. You fight the battles humanity must win, every generation, in order to stay human. Do you understand?"

"I… I don't know."

"You must try, Percy. Because whether or not you are the child of the prophecy, Kronos thinks you might be. And after today, he will finally despair of turning you to his side. That is the only reason he hasn't killed you yet, you know. As soon as he's sure he can't use you, he will destroy you."

"You talk like you know him."

Chiron pursed his lips. "I do know him."