"One on one," I challenged Luke. "What are you afraid of?"

Luke curled his lip. The soldiers who were about to kill us hesitated, waiting for his order.

Before he could say anything, Agrius, the bear-man, burst onto the deck leading a flying horse. It was the first pure-black pegasus I'd ever seen, with wings like a giant raven. The pegasus mare bucked and whinnied. I could understand her thoughts. She was calling Agrius and Luke some names so bad Chiron would've washed her muzzle out with saddle soap.

"Sir!" Agrius called, dodging a pegasus hoof. "Your steed is ready!"

Luke kept his eyes on me.

"I told you last summer, Percy," he said. "You can't bait me into a fight."

"And you keep avoiding one," I noticed. "Scared your warriors will see you get whipped?"

Luke glanced at his men, and he saw I'd trapped him. If he backed down now, he would look weak. If he fought me, he'd lose valuable time chasing after Clarisse. For my part, the best I could hope for was to distract him, giving my friends a chance to escape. If anybody could think of a plan to get them out of there, Annabeth could. On the downside, I knew how good Luke was at sword-fighting.

"I'll kill you quickly," he decided, and raised his weapon. Backbiter was a foot longer than my own sword. Its blade glinted with an evil gray-and-gold light where the human steel had been melded with celestial bronze. I could almost feel the blade fighting against itself, like two opposing magnets bound together. I didn't know how the blade had been made, but I sensed a tragedy. Someone had died in the process. Luke whistled to one of his men, who threw him a round leather-and-bronze shield.

He grinned at me wickedly.

"Luke," Annabeth said, "at least give him a shield."

"Sorry, Annabeth," he said. "You bring your own equipment to this party."

The shield was a problem. Fighting two-handed with just a sword gives you more power, but fighting one-handed with a shield gives you better defense and versatility. There are more moves, more options, more ways to kill. I thought back to Chiron, who'd told me to stay at camp no matter what, and learn to fight. Now I was going to pay for not listening to him.

Luke lunged and almost killed me on the first try. His sword went under my arm, slashing through my shirt and grazing my ribs.

I jumped back, then counterattacked with Riptide, but Luke slammed my blade away with his shield.

"My, Percy," Luke chided. "You're out of practice."

He came at me again with a swipe to the head. I parried, returned with a thrust. He sidestepped easily.

The cut on my ribs stung. My heart was racing. When Luke lunged again, I jumped backward into the swimming pool and felt a surge of strength. I spun underwater, creating a funnel cloud, and blasted out of the deep end, straight at Luke's face.

The force of the water knocked him down, spluttering and blinded. But before I could strike, he rolled aside and was on his feet again.

I attacked and sliced off the edge of his shield, but that didn't even faze him. He dropped to a crouch and jabbed at my legs. Suddenly my thigh was on fire, with a pain so intense I collapsed. My jeans were ripped above the knee. I was hurt. I didn't know how badly. Luke hacked downward and I rolled behind a deck chair. I tried to stand, but my leg wouldn't take the weight.

"Perrrrrcy!" Grover bleated.

I rolled again as Luke's sword slashed the deck chair in half, metal pipes and all.

I clawed toward the swimming pool, trying hard not to black out. I'd never make it. Luke knew it, too. He advanced slowly, smiling. The edge of his sword was tinged with red.

"One thing I want you to watch before you die, Percy." He looked at the bear-man Oreius, who was still holding Annabeth and Grover by the necks. "You can eat your dinner now, Oreius. Bon appetit."

"He-he! He-he!" The bear-man lifted my friends and bared his teeth.

That's when all Hades broke loose.

Whish!

A red-feathered arrow sprouted from Oreius's mouth. With a surprised look on his hairy face, he crumpled to the deck.

"Brother!" Agrius wailed. He let the pegasus's reins go slack just long enough for the black steed to kick him in the head and fly away free over Miami Bay.

For a split second, Luke's guards were too stunned to do anything except watch the bear twins' bodies dissolve into smoke.

Then there was a wild chorus of war cries and hooves thundering against metal. A dozen centaurs charged out of the main stairwell.

"Ponies!" Tyson cried with delight.

My mind had trouble processing everything I saw. Chiron was among the crowd, but his relatives were almost nothing like him. There were centaurs with black Arabian stallion bodies, others with gold palomino coats, others with orange-and-white spots like paint horses. Some wore brightly colored T-shirts with Day-Glo letters that said PARTY PONIES: SOUTH FLORIDA CHAPTER. Some were armed with bows, some with baseball bats, some with paintball guns. One had his face painted like a Comanche warrior and was waving a large orange Styrofoam hand making a big Number I. Another was bare-chested and painted entirely green. A third had googly-eye glasses with the eyeballs bouncing around on Slinky coils, and one of those baseball caps with soda-can-and-straw attachments on either side.

They exploded onto the deck with such ferocity and color that for a moment even Luke was stunned. I couldn't tell whether they had come to celebrate or attack.

Apparently both. As Luke was raising his sword to rally his troops, a centaur shot a custom-made arrow with a leather boxing glove on the end. It smacked Luke in the face and sent him crashing into the swimming pool.

His warriors scattered. I couldn't blame them. Facing the hooves of a rearing stallion is scary enough, but when it's a centaur, armed with a bow and whooping it up in a soda-drinking hat, even the bravest warrior would retreat.

"Come get some!" yelled one of the party ponies.

They let loose with their paintball guns. A wave of blue and yellow exploded against Luke's warriors, blinding them and splattering them from head to toe. They tried to run, only to slip and fall.

Chiron galloped toward Annabeth and Grover, neatly plucked them off the deck, and deposited them on his back.

I tried to get up, but my wounded leg still felt like it was on fire.

Luke was crawling out of the pool.

"Attack, you fools. " he ordered his troops. Somewhere down below deck, a large alarm bell thrummed.

I knew any second we would be swamped by Luke's reinforcements. Already, his warriors were getting over their surprise, coming at the centaurs with swords and spears drawn.

Tyson slapped half a dozen of them aside, knocking them over the guardrail into Miami Bay. But more warriors were coming up the stairs.

"Withdraw, brethren!" Chiron said.

"You won't get away with this, horse man!" Luke shouted. He raised his sword, but got smacked in the face with another boxing glove arrow, and sat down hard in a deck chair.

A palomino centaur hoisted me onto his back. "Dude, get your big friend!"

"Tyson!" I yelled. "Come on!"

Tyson dropped the two warriors he was about to tie into a knot and jogged after us. He jumped on the centaur's back.

"Dude!" the centaur groaned, almost buckling under Tyson's weight. "Do the words 'low-carb diet' mean anything to you?"

Luke's warriors were organizing themselves into a phalanx. But by the time they were ready to advance, the centaurs had galloped to the edge of the deck and fearlessly jumped the guardrail, as if it were a steeplechase and not ten stories above the ground. I was sure we were going to die. We plummeted toward the docks, but the centaurs hit the asphalt with hardly a jolt and galloped off, whooping and yelling taunts at the Princess Andromeda as we raced into the streets of downtown Miami.