On the other side of the creek, the underbrush exploded. Five Ares warriors came yelling and screaming out of the dark.

"Cream the punk!" Clarisse screamed.

Her ugly pig eyes glared through the slits of her helmet. She brandished a five-foot-long spear, its barbed metal tip flickering with red light. Her siblings had only the standard-issue bronze swords—not that that made me feel any better.

They charged across the stream. There was no help in sight. I could run. Or I could defend myself against half the Ares cabin.

I managed to sidestep the first kid's swing, but these guys were not as stupid the Minotaur. They surrounded me, and Clarisse thrust at me with her spear. My shield deflected the point, but I felt a painful tingling all over my body. My hair stood on end. My shield arm went numb, and the air burned.

Electricity. Her stupid spear was electric. I fell back.

Another Ares guy slammed me in the chest with the butt of his sword and I hit the dirt.

They could've kicked me into jelly, but they were too busy laughing.

"Give him a haircut," Clarisse said. "Grab his hair."

I managed to get to my feet. I raised my sword, but Clarisse slammed it aside with her spear as sparks flew. Now both my arms felt numb.

"Oh, wow," Clarisse said. "I'm scared of this guy. Really scared."

"The flag is that way," I told her. I wanted to sound angry, but I was afraid it didn't come out that way.

"Yeah," one of her siblings said. "But see, we don't care about the flag. We care about a guy who made our cabin look stupid."

"You do that without my help," I told them. It probably wasn't the smartest thing to say.

Two of them came at me. I backed up toward the creek, tried to raise my shield, but Clarisse was too fast. Her spear stuck me straight in the ribs. If I hadn't been wearing an armored breastplate, I would've been shish-ke-babbed. As it was, the electric point just about shocked my teeth out of my mouth. One of her cabinmates slashed his sword across my arm, leaving a good-size cut.

Seeing my own blood made me dizzy—warm and cold at the same time.

"No maiming," I managed to say.

"Oops," the guy said. "Guess I lost my dessert privilege.

He pushed me into the creek and I landed with a splash. They all laughed. I figured as soon as they were through being amused, I would die. But then something happened. The water seemed to wake up my senses, as if I'd just had a bag of my mom's double-espresso jelly beans.

Clarisse and her cabinmates came into the creek to get me, but I stood to meet them. I knew what to do. I swung the flat of my sword against the first guy's head and knocked his helmet clean off. I hit him so hard I could see his eyes vibrating as he crumpled into the water.

Ugly Number Two and Ugly Number Three came at me. I slammed one in the face with my shield and used my sword to shear off the other guy's horsehair plume. Both of them backed up quick. Ugly Number Four didn't look really anxious to attack, but Clarisse kept coming, the point of her spear crackling with energy. As soon as she thrust, I caught the shaft between the edge of my shield and my sword, and I snapped it like a twig.

"Ah!" she screamed. "You idiot! You corpse-breath worm!"

She probably would've said worse, but I smacked her between the eyes with my sword-butt and sent her stumbling backward out of the creek.

Then I heard yelling, elated screams, and I saw Luke racing toward the boundary line with the red team's banner lifted high. He was flanked by a couple of Hermes guys covering his retreat, and a few Apollos behind them, fighting off the Hephaestus kids. The Ares folks got up, and Clarisse muttered a dazed curse.

"A trick!" she shouted. "It was a trick."

They staggered after Luke, but it was too late. Everybody converged on the creek as Luke ran across into friendly territory. Our side exploded into cheers. The red banner shimmered and turned to silver. The boar and spear were replaced with a huge caduceus, the symbol of cabin eleven. Everybody on the blue team picked up Luke and started carrying him around on their shoulders. Chiron cantered out from the woods and blew the conch horn.

The game was over. We'd won.

I was about to join the celebration when Annabeth's voice, right next to me in the creek, said, "Not bad, hero."

I looked, but she wasn't there.

"Where the heck did you learn to fight like that?" she asked. The air shimmered, and she materialized, holding a Yankees baseball cap as if she'd just taken it off her head.

I felt myself getting angry. I wasn't even fazed by the fact that she'd just been invisible. "You set me up," I said. "You put me here because you knew Clarisse would come after me, while you sent Luke around the flank. You had it all figured out."

Annabeth shrugged. "I told you. Athena always, always has a plan."

"A plan to get me pulverized."

"I came as fast as I could. I was about to jump in, but ..." She shrugged. "You didn't need help."

Then she noticed my wounded arm. "How did you do that?"

"Sword cut," I said. "What do you think?"

"No. It was a sword cut. Look at it."

The blood was gone. Where the huge cut had been, there was a long white scratch, and even that was fading. As I watched, it turned into a small scar, and disappeared.

"I—I don't get it," I said.

Annabeth was thinking hard. I could almost see the gears turning. She looked down at my feet, then at Clarisse's broken spear, and said, "Step out of the water, Percy."

"What—"

"Just do it."

I came out of the creek and immediately felt bone tired. My arms started to go numb again. My adrenaline rush left me. I almost fell over, but Annabeth steadied me.

"Oh, Styx," she cursed. "This is not good. I didn't want ... I assumed it would be Zeus... ."

Before I could ask what she meant, I heard that canine growl again, but much closer than before. A howl ripped through the forest.

The campers' cheering died instantly. Chiron shouted something in Ancient Greek, which I would realize, only later, I had understood perfectly: "Stand ready! My bow!"

Annabeth drew her sword.

There on the rocks just above us was a black hound the size of a rhino, with lava-red eyes and fangs like daggers.

It was looking straight at me.

Nobody moved except Annabeth, who yelled, "Percy, run!"

She tried to step in front of me, but the hound was too fast. It leaped over her—an enormous shadow with teeth—and just as it hit me, as I stumbled backward and felt its razor-sharp claws ripping through my armor, there was a cascade of thwacking sounds, like forty pieces of paper being ripped one after the other. From the hounds neck sprouted a cluster of arrows. The monster fell dead at my feet.

By some miracle, I was still alive. I didn't want to look underneath the ruins of my shredded armor. My chest felt warm and wet, and I knew I was badly cut. Another second, and the monster would've turned me into a hundred pounds of delicatessen meat.

Chiron trotted up next to us, a bow in his hand, his face grim.

"Di immortales!" Annabeth said. "That's a hellhound from the Fields of Punishment. They don't ... they're not supposed to ..."

"Someone summoned it," Chiron said. "Someone inside the camp."

Luke came over, the banner in his hand forgotten, his moment of glory gone.

Clarisse yelled, "It's all Percy's fault! Percy summoned it!"

"Be quiet, child," Chiron told her.

We watched the body of the hellhound melt into shadow, soaking into the ground until it disappeared.

"You're wounded," Annabeth told me. "Quick, Percy, get in the water."

"I'm okay."

"No, you're not," she said. "Chiron, watch this."

I was too tired to argue. I stepped back into the creek, the whole camp gathering around me.

Instantly, I felt better. I could feel the cuts on my chest closing up. Some of the campers gasped.

"Look, I—I don't know why," I said, trying to apologize. "I'm sorry...."

But they weren't watching my wounds heal. They were staring at something above my head.

"Percy," Annabeth said, pointing. "Um ..."

By the time I looked up, the sign was already fading, but I could still make out the hologram of green light, spinning and gleaming. A three-tipped spear: a trident.

"Your father," Annabeth murmured. "This is really not good."

"It is determined," Chiron announced.

All around me, campers started kneeling, even the Ares cabin, though they didn't look happy about it.

"My father?" I asked, completely bewildered.

"Poseidon," said Chiron. "Earthshaker, Stormbringer, Father of Horses. Hail, Perseus Jackson, Son of the Sea God."

9. I AM OFFERED A QUEST

The next morning, Chiron moved me to cabin three.

I didn't have to share with anybody. I had plenty of room for all my stuff: the Minotaur's horn, one set of spare clothes, and a toiletry bag. I got to sit at my own dinner table, pick all my own activities, call "lights out" whenever I felt like it, and not listen to anybody else.

And I was absolutely miserable.

Just when I'd started to feel accepted, to feel I had a home in cabin eleven and I might be a normal kid—or as normal as you can be when you're a half-blood—I'd been separated out as if I had some rare disease.

Nobody mentioned the hellhound, but I got the feeling they were all talking about it behind my back. The attack had scared everybody. It sent two messages: one, that I was the son of the Sea God; and two, monsters would stop at nothing to kill me. They could even invade a camp that had always been considered safe.

The other campers steered clear of me as much as possible. Cabin eleven was too nervous to have sword class with me after what I'd done to the Ares folks in the woods, so my lessons with Luke became one-on-one. He pushed me harder than ever, and wasn't afraid to bruise me up in the process.

"You're going to need all the training you can get," he promised, as we were working with swords and flaming torches. "Now let's try that viper-beheading strike again. Fifty more repetitions."

Annabeth still taught me Greek in the mornings, but she seemed distracted. Every time I said something, she scowled at me, as if I'd just poked her between the eyes.

After lessons, she would walk away muttering to herself: "Quest ... Poseidon? ... Dirty rotten ... Got to make a plan ..."

Even Clarisse kept her distance, though her venomous looks made it clear she wanted to kill me for breaking her magic spear. I wished she would just yell or punch me or something. I'd rather get into fights every day than be ignored.

I knew somebody at camp resented me, because one night I came into my cabin and found a mortal newspaper dropped inside the doorway, a copy of the New York Daily News, opened to the Metro page. The article took me almost an hour to read, because the angrier I got, the more the words floated around on the page.

BOY AND MOTHER STILL MISSING AFTER

FREAK CAR ACCIDENT

BY EILEEN SMYTHE

Sally Jackson and son Percy are still missing one week after their mysterious disappearance. The family's badly burned '78 Camaro was discovered last Saturday on a north Long Island road with the roof ripped off and the front axle broken. The car had flipped and skidded for several hundred feet before exploding.