If you've ever seen a crab's mouth, all foamy and gross with whiskers and snapping bits, you can imagine this one didn't look any better blown up to billboard size. Its beady black eyes glared at me, and I could see intelligence in them—and hate. The fact that I was the son of the sea god was not going to win me any points with Mr. Crabby.

"FFFFffffff," it hissed, sea foam dripping from its mouth. The smell coming off it was like a garbage can full of fish sticks that had been sitting in the sun all week.

Alarms blared. Soon I was going to have lots of company and I had to keep moving.

"Hey, crabby." I inched around the edge of the courtyard. "I'm just gonna scoot around you so—"

The crab moved with amazing speed. It scuttled out of the fountain and came straight at me, pincers snapping. 1 dove into a gift shop, plowing through a rack of T-shirts. A crab pincer smashed the glass walls to pieces and raked across the room. I dashed back outside, breathing heavily, but Mr. Crabby turned and followed.

"There!" a voice said from a balcony above me. "Intruder!"

If I'd wanted to create a distraction, I'd succeeded, but this was not where I wanted to fight. If I got pinned down in the center of the ship, I was crab chow.

The demonic crustacean lunged at me. I sliced with Riptide, taking off the tip of its claw. It hissed and foamed, but didn't seem very hurt.

I tried to remember anything from the old stories that might help with this thing. Annabeth had told me about a monster crab—something about Hercules crushing it under his foot? That wasn't going to work here. This crab was slightly bigger than my Reeboks.

Then a weird thought occurred to me. Last Christmas, my mom and I had brought Paul Blofis to our old cabin at Montauk, where we'd been going forever. Paul had taken me crabbing, and when he'd brought up a net full of the things, he'd shown me how crabs have a chink in their armor, right in the middle of their ugly bellies.

The only problem was getting to the ugly belly.

I glanced at the fountain, then at the marble floor, already slick from scuttling crab tracks. I held out my hand, concentrating on the water, and the fountain exploded. Water sprayed everywhere, three stories high, dousing the balconies and the elevators and the windows of the shops. The crab didn't care. It loved water. It came at me sideways, snapping and hissing, and I ran straight at it, screaming, "AHHHHHHH!"

Just before we collided, I hit the ground baseball-style and slid on the wet marble floor straight under the creature. It was like sliding under a seven-ton armored vehicle. All the crab had to do was sit and squash me, but before it realized what was going on, I jabbed Riptide into the chink in its armor, let go of the hilt, and pushed myself out the backside.

The monster shuddered and hissed. Its eyes dissolved. Its shell turned bright red as its insides evaporated. The empty shell clattered to the floor in a massive heap.

I didn't have time to admire my handiwork. I ran for the nearest stairs while all around me monsters and demigods shouted orders and strapped on their weapons. I was empty-handed. Riptide, being magic, would appear in my pocket sooner or later, but for now it was stuck somewhere under the wreckage of the crab, and I had no time to retrieve it.

In the elevator foyer on deck eight, a couple of dracaenae slithered across my path. From the waist up, they were women with green scaly skin, yellow eyes, and forked tongues. From the waist down, they had double snake trunks instead of legs. They held spears and weighted nets, and I knew from experience they could use them.

"What isss thisss?" one said. "A prize for Kronosss!"

I wasn't in the mood to play break-the-snake, but in front of me was a stand with a model of the ship, like a YOU ARE HERE display. I ripped the model off the pedestal and hurled it at the first iracaena. The boat smacked her in the face and she went down with the ship. I jumped over her, grabbed her friend's spear, and swung her around. She slammed into the elevator, and I kept running toward the front of the ship.

"Get him!" she screamed.

Hellhounds bayed. An arrow from somewhere whizzed past my face and impaled itself in the mahogany-paneled wall of the stairwell.

I didn't care—as long as I got the monsters away from the engine room and gave Beckendorf more time.

As I was running up the stairwell, a kid charged down. He looked like he'd just woken up from a nap. His armor was half on. He drew his sword and yelled, "Kronos!" but he sounded more scared than angry. He couldn't have been more than twelve—about the same age I was when I'd first arrived at Camp Half-Blood.

That thought depressed me. This kid was getting brainwashed—trained to hate the gods and lash out because he'd been born half Olympian. Kronos was using him, and yet the kid thought I was his enemy.

No way was I going to hurt him. I didn't need a weapon for this. I stepped inside his strike and grabbed his wrist, slamming it against the wall. His sword clattered out of his hand.

Then I did something I hadn't planned on. It was probably stupid. It definitely jeopardized our mission, but I couldn't help it.

"If you want to live," I told him, "get off this ship now. Tell the other demigods." Then I shoved him down the stairs and sent him tumbling to the next floor.

I kept climbing.

Bad memories: a hallway ran past the cafeteria. Annabeth, my half brother Tyson, and I had sneaked through here three years ago on my first visit.

I burst outside onto the main deck. Off the port bow, the sky was darkening from purple to black. A swimming pool glowed between two glass towers with more balconies and restaurant decks. The whole upper ship seemed eerily deserted.

All I had to do was cross to the other side. Then I could take the staircase down to the helipad—our emergency rendezvous point. With any luck, Beckendorf would meet me there. We'd jump into the sea. My water powers would protect us both, and we'd detonate the charges from a quarter mile away.

I was halfway across the deck when the sound of a voice made me freeze. "You're late, Percy."

Luke stood on the balcony above me, a smile on his scarred face. He wore jeans, a white T-shirt, and flip-flops, like he was just a normal college-age guy, but his eyes told the truth. They were solid gold.

"We've been expecting you for days." At first he sounded normal, like Luke. But then his face twitched. A shudder passed through his body as though he'd just drunk something really nasty. His voice became heavier, ancient, and powerful—the voice of the Titan lord Kronos. The words scraped down my spine like a knife blade. "Come, bow before me."

"Yeah, that'll happen," I muttered.

Laistrygonian giants filed in on either side of the swimming pool as if they'd been waiting for a cue. Each was eight feet tall with tattooed arms, leather armor, and spiked clubs. Demigod archers appeared on the roof above Luke. Two hellhounds leaped down from the opposite balcony and snarled at me. Within seconds I was surrounded. A trap: there's no way they could've gotten into position so fast unless they'd known I was coming.

I looked up at Luke, and anger boiled inside me. I didn't know if Luke's consciousness was even still alive inside that body. Maybe, the way his voice had changed . . . or maybe it was just Kronos adapting to his new form. I told myself it didn't matter. Luke had been twisted and evil long before Kronos possessed him.

A voice in my head said: I have to fight him eventually. Why not now?

According to that big prophecy, I was supposed to make a choice that saved or destroyed the world when I was sixteen. That was only seven days away. Why not now? If I really had the power, what difference would a week make? I could end this threat right here by taking down Kronos. Hey, I'd fought monsters and gods before.