The cord, a familiar voice said. Remember your lifeline, dummy!

Suddenly there was a tug in my lower back. The current pulled at me, but it wasn't carrying me away anymore. I imagined the string in my back keeping me tied to the shore.

"Hold on, Seaweed Brain." It was Annabeth's voice, much clearer now. "You're not getting away from me that easily."

The cord strengthened.

I could see Annabeth now—standing barefoot above me on the canoe lake pier. I'd fallen out of my canoe. That was it. She was reaching out her hand to haul me up, and she was trying not to laugh. She wore her orange camp T-shirt and jeans. Her hair was tucked up in her Yankees cap, which was strange because that should have made her invisible.

"You are such an idiot sometimes." She smiled. "Come on. Take my hand."

Memories came flooding back to me—sharper and more colorful. I stopped dissolving. My name was Percy Jackson. I reached up and took Annabeth's hand.

Suddenly I burst out of the river. I collapsed on the sand, and Nico scrambled back in surprise.

"Are you okay?" he stammered. "Your skin. Oh, gods. You're hurt!"

My arms were bright red. I felt like every inch of my body had been broiled over a slow flame.

I looked around for Annabeth, though I knew she wasn't here. It had seemed so real.

"I'm fine . . . I think." The color of my skin turned back to normal. The pain subsided. Mrs. O'Leary came up and sniffed me with concern. Apparently I smelled really interesting.

"Do you feel stronger?" Nico asked.

Before I could decide what I felt, a voice boomed, "THERE!"

An army of the dead marched toward us. A hundred skeletal Roman legionnaires led the way with shields and spears. Behind them came an equal number of British redcoats with bayonets fixed. In the middle of the host, Hades himself rode a black-and-gold chariot pulled by nightmare horses, their eyes and manes smoldering with fire.

"You will not escape me this time, Percy Jackson!" Hades bellowed. "Destroy him!"

"Father, no!" Nico shouted, but it was too late. The front line of Roman zombies lowered their spears and advanced.

Mrs. O'Leary growled and got ready to pounce. Maybe that's what set me off. I didn't want them hurting my dog. Plus, I was tired of Hades being a big bully. If I was going to die, I might as well go down fighting.

I yelled, and the River Styx exploded. A black tidal wave smashed into the legionnaires. Spears and shields flew everywhere. Roman zombies began to dissolve, smoke coming off their bronze helmets.

The redcoats lowered their bayonets, but I didn't wait for them. I charged.

It was the stupidest thing I've ever done. A hundred muskets fired at me, point blank. All of them missed. I crashed into their line and started hacking with Riptide. Bayonets jabbed. Swords slashed. Guns reloaded and fired. Nothing touched me.

I whirled through the ranks, slashing redcoats to dust, one after the other. My mind went on autopilot: stab, dodge, cut, deflect, roll. Riptide was no longer a sword. It was an arc of pure destruction.

I broke through the enemy line and leaped into the black chariot. Hades raised his staff. A bolt of dark energy shot toward me, but I deflected it off my blade and slammed into him. The god and I both tumbled out of the chariot.

The next thing I knew, my knee was planted on Hades's chest. I was holding the collar of his royal robes in one fist, and the tip of my sword was poised right over his face.

Silence. The army did nothing to defend their master. I glanced back and realized why. There was nothing left of them but weapons in the sand and piles of smoking, empty uniforms. I had destroyed them all.

Hades swallowed. "Now, Jackson, listen here. . . ."

He was immortal. There was no way I could kill him, but gods can be wounded. I knew that firsthand, and I figured a sword in the face wouldn't feel too good.

"Just because I'm a nice person," I snarled, "I'll let you go. But first, tell me about that trap!"

Hades melted into nothing, leaving me holding empty black robes.

I cursed and got to my feet, breathing heavily. Now that the danger was over, I realized how tired I was. Every muscle in my body ached. I looked down at my clothes. They were slashed to pieces and full of bullet holes, but I was fine. Not a mark on me.

Nico's mouth hung open. "You just . . . with a sword . . . you just—"

"I think the river thing worked," I said.

"Oh gee," he said sarcastically. "You think?"

Mrs. O'Leary barked happily and wagged her tail. She bounded around, sniffing empty uniforms and hunting for bones. I lifted Hades's robe. I could still see the tormented faces shimmering in the fabric.

I walked to the edge of the river. "Be free."

I dropped the robe in the water and watched as it swirled away, dissolving in the current.

"Go back to your father," I told Nico. "Tell him he owes me for letting him go. Find out what's going to happen to Mount Olympus and convince him to help."

Nico stared at me. "I . . . I can't. He'll hate me now. I mean . . . even more."

"You have to," I said. "You owe me too."

His ears turned red. "Percy, I told you I was sorry. Please . . . let me come with you. I want to fight."

"You'll be more help down here."

"You mean you don't trust me anymore," he said miserably.

I didn't answer. I didn't know what I meant. I was too stunned by what I'd just done in battle to think clearly.

"Just go back to your father," I said, trying not to sound too harsh. "Work on him. You're the only person who might be able to get him to listen."

"That's a depressing thought." Nico sighed. "All right. I'll do my best. Besides, he's still hiding something from me about my mom. Maybe I can find out what."

"Good luck. Now Mrs. O'Leary and I have to go."

"Where?" Nico said.

I looked at the cave entrance and thought about the long climb back to the world of the living. "To get this war started. It's time I found Luke."




I love New York. You can pop out of the Underworld in Central Park, hail a taxi, head down Fifth Avenue with a giant hellhound loping along behind you, and nobody even looks at you funny.

Of course, the Mist helped. People probably couldn't see Mrs. O'Leary, or maybe they thought she was a large, loud, very friendly truck.

I took the risk of using my mom's cell phone to call Annabeth for the second time. I'd called her once from the runnel but only reached her voice mail. I'd gotten surprisingly good reception, seeing as I was at the mythological center of the world and all, but I didn't want to see what my mom's roaming charges were going to be.

This time, Annabeth picked up.

"Hey," I said. "You get my message?"

"Percy, where have you been? Your message said almost nothing! We've been worried sick!"

"I'll fill you in later," I said, though how I was going to do that I had no idea. "Where are you?"

"We're on our way like you asked, almost to the Queens—Midtown Tunnel. But, Percy, what are you planning? We've left the camp virtually undefended, and there's no way the gods—"

"Trust me," I said. "I'll see you there."

I hung up. My hands were trembling. I wasn't sure if it was a leftover reaction from my dip in the Styx, or anticipation of what I was about to do. If this didn't work, being invulnerable wasn't going to save me from getting blasted to bits.

It was late afternoon when the taxi dropped me at the Empire State Building. Mrs. O'Leary bounded up and down Fifth Avenue, licking cabs and sniffing hot dog carts. Nobody seemed to notice her, although people did swerve away and look confused when she came close.

I whistled for her to heel as three white vans pulled up to the curb. They said Delphi Strawberry Service, which was the cover name for Camp Half-Blood. I'd never seen all three vans in the same place at once, though I knew they shuttled our fresh produce into the city.

The first van was driven by Argus, our many-eyed security chief. The other two were driven by harpies, who are basically demonic human/chicken hybrids with bad attitudes. We used the harpies mostly for cleaning the camp, but they did pretty well in midtown traffic too.

The doors slid open. A bunch of campers climbed out, some of them looking a little green from the long drive. I was glad so many had come: Pollux, Silena Beauregard, the Stoll brothers, Michael Yew, Jake Mason, Katie Gardner, and Annabeth, along with most of their siblings. Chiron came out of the van last. His horse half was compacted into his magic wheelchair, so he used the handicap lift. The Ares cabin wasn't here, but I tried not to get too angry about that. Clarisse was a stubborn idiot. End of story.

I did a head count: forty campers in all.

Not many to fight a war, but it was still the largest group of half-bloods I'd ever seen gathered in one place outside camp. Everyone looked nervous, and I understood why. We were probably sending out so much demigod aura that every monster in the northeastern United States knew we were here.

As I looked at their faces—all these campers I'd known for so many summers—a nagging voice whispered in my mind: One of them is a spy.

But I couldn't dwell on that. They were my friends. I needed them.

Then I remembered Kronos's evil smile. You can't count on friends. They will always let you down.

Annabeth came up to me. She was dressed in black camouflage with her Celestial bronze knife strapped to her arm and her laptop bag slung over her shoulder—ready for stabbing or surfing the Internet, whichever came first.

She frowned. "What is it?"

"What's what?" I asked.

"You're looking at me funny."

I realized I was thinking about my strange vision of Annabeth pulling me out of the Styx River. "It's, uh, nothing." I turned to the rest of the group. "Thanks for coming, everybody. Chiron, after you."

My old mentor shook his head. "I came to wish you luck, my boy. But I make it a point never to visit Olympus unless I am summoned."

"But you're our leader."

He smiled. "I am your trainer, your teacher. That is not the same as being your leader. I will go gather what allies I can. It may not be too late to convince my brother centaurs to help. Meanwhile, you called the campers here, Percy. You are the leader."

I wanted to protest, but everybody was looking at me expectantly, even Annabeth.

I took a deep breath. "Okay, like I told Annabeth on the phone, something bad is going to happen by tonight. Some kind of trap. We've got to get an audience with Zeus and convince him to defend the city. Remember, we can't take no for an answer."

I asked Argus to watch Mrs. O'Leary, which neither of them looked happy about.

Chiron shook my hand. "You'll do well, Percy. Just remember your strengths and beware your weaknesses."

It sounded eerily close to what Achilles had told me. Then I remembered Chiron had taught Achilles. That didn't exactly reassure me, but I nodded and tried to give him a confident smile.

"Let's go," I told the campers.

A security guard was sitting behind the desk in the lobby, reading a big black book with a flower on the cover. He glanced up when we all filed in with our weapons and armor clanking. "School group? We're about to close up."