Her hands tightened around the pier railing. I got the feeling I'd just trespassed on a sensitive subject.

"My dad is a professor at West Point," she said. "I haven't seen him since I was very small. He teaches American history."

"He's human."

"What? You assume it has to be a male god who finds a human female attractive? How sexist is that?"

"Who's your mom, then?"

"Cabin six."

"Meaning?"

Annabeth straightened. "Athena. Goddess of wisdom and battle."

Okay, I thought. Why not?

"And my dad?"

"Undetermined," Annabeth said, "like I told you before. Nobody knows."

"Except my mother. She knew."

"Maybe not, Percy. Gods don't always reveal their identities."

"My dad would have. He loved her."

Annabeth gave me a cautious look. She didn't want to burst my bubble. "Maybe you're right. Maybe he'll send a sign. That's the only way to know for sure: your father has to send you a sign claiming you as his son. Sometimes it happens.

"You mean sometimes it doesn't?"

Annabeth ran her palm along the rail. "The gods are busy. They have a lot of kids and they don't always ... Well, sometimes they don't care about us, Percy. They ignore us."

I thought about some of the kids I'd seen in the Hermes cabin, teenagers who looked sullen and depressed, as if they were waiting for a call that would never come. I'd known kids like that at YancyAcademy, shuffled off to boarding school by rich parents who didn't have the time to deal with them. But gods should behave better.

"So I'm stuck here," I said. "That's it? For the rest of my life?"

"It depends," Annabeth said. "Some campers only stay the summer. If you're a child of Aphrodite or Demeter, you're probably not a real powerful force. The monsters might ignore you, so you can get by with a few months of summer training and live in the mortal world the rest of the year. But for some of us, it's too dangerous to leave. We're year-rounders. In the mortal world, we attract monsters. They sense us. They come to challenge us. Most of the time, they'll ignore us until we're old enough to cause trouble—about ten or eleven years old, but after that, most demigods either make their way here, or they get killed off. A few manage to survive in the outside world and become famous. Believe me, if I told you the names, you'd know them. Some don't even realize they're demigods. But very, very few are like that."

"So monsters can't get in here?"

Annabeth shook her head. "Not unless they're intentionally stocked in the woods or specially summoned by somebody on the inside."

"Why would anybody want to summon a monster?"

"Practice fights. Practical jokes."

"Practical jokes?"

"The point is, the borders are sealed to keep mortals and monsters out. From the outside, mortals look into the valley and see nothing unusual, just a strawberry farm."

"So ... you're a year-rounder?"

Annabeth nodded. From under the collar of her T-shirt she pulled a leather necklace with five clay beads of different colors. It was just like Luke's, except Annabeth's also had a big gold ring strung on it, like a college ring.

"I've been here since I was seven," she said. "Every August, on the last day of summer session, you get a bead for surviving another year. I've been here longer than most of the counselors, and they're all in college."

"Why did you come so young?"

She twisted the ring on her necklace. "None of your business."

"Oh." I stood there for a minute in uncomfortable silence. "So ... I could just walk out of here right now if I wanted to?"

"It would be suicide, but you could, with Mr. D's or Chiron's permission. But they wouldn't give permission until the end of the summer session unless ..."

"Unless?"

"You were granted a quest. But that hardly ever happens. The last time ..."

Her voice trailed off. I could tell from her tone that the last time hadn't gone well.

"Back in the sick room," I said, "when you were feeding me that stuff—"

"Ambrosia."

"Yeah. You asked me something about the summer solstice."

Annabeth's shoulders tensed. "So you do know something?"

"Well... no. Back at my old school, I overheard Grover and Chiron talking about it. Grover mentioned the summer solstice. He said something like we didn't have much time, because of the deadline. What did that mean?"

She clenched her fists. "I wish I knew. Chiron and the satyrs, they know, but they won't tell me. Something is wrong in Olympus, something pretty major. Last time I was there, everything seemed so normal."

"You've been to Olympus?"

"Some of us year-rounders—Luke and Clarisse and I and a few others—we took a field trip during winter solstice. That's when the gods have their big annual council."

"But... how did you get there?"

"The Long Island Railroad, of course. You get off at Penn Station. EmpireStateBuilding, special elevator to the six hundredth floor." She looked at me like she was sure I must know this already. "You are a New Yorker, right?"

"Oh, sure." As far as I knew, there were only a hundred and two floors in the EmpireStateBuilding, but I decided not to point that out.

"Right after we visited," Annabeth continued, "the weather got weird, as if the gods had started fighting. A couple of times since, I've overheard satyrs talking. The best I can figure out is that something important was stolen. And if it isn't returned by summer solstice, there's going to be trouble. When you came, I was hoping ... I mean— Athena can get along with just about anybody, except for Ares. And of course she's got the rivalry with Poseidon. But, I mean, aside from that, I thought we could work together. I thought you might know something."

I shook my head. I wished I could help her, but I felt too hungry and tired and mentally overloaded to ask any more questions.

"I've got to get a quest," Annabeth muttered to herself. "I'm not too young. If they would just tell me the problem ..."

I could smell barbecue smoke coming from somewhere nearby. Annabeth must've heard my stomach growl. She told me to go on, she'd catch me later. I left her on the pier, tracing her finger across the rail as if drawing a battle plan.

Back at cabin eleven, everybody was talking and horsing around, waiting for dinner. For the first time, I noticed that a lot of the campers had similar features: sharp noses, upturned eyebrows, mischievous smiles. They were the kind of kids that teachers would peg as troublemakers. Thankfully, nobody paid much attention to me as I walked over to my spot on the floor and plopped down with my minotaur horn.. . . ..

The counselor, Luke, came over. He had the Hermes family resemblance, too. It was marred by that scar on his right cheek, but his smile was intact.

"Found you a sleeping bag," he said. "And here, I stole you some toiletries from the camp store."

I couldn't tell if he was kidding about the stealing part.

I said, "Thanks."

"No prob." Luke sat next to me, pushed his back against the wall. "Tough first day?"

"I don't belong here," I said. "I don't even believe in gods."

"Yeah," he said. "That's how we all started. Once you start believing in them? It doesn't get any easier."

The bitterness in his voice surprised me, because Luke seemed like a pretty easygoing guy. He looked like he could handle just about anything.

"So your dad is Hermes?" I asked.

He pulled a switchblade out of his back pocket, and for a second I thought he was going to gut me, but he just scraped the mud off the sole of his sandal. "Yeah. Hermes."

"The wing-footed messenger guy."

"That's him. Messengers. Medicine. Travelers, merchants, thieves. Anybody who uses the roads. That's why you're here, enjoying cabin eleven's hospitality. Hermes isn't picky about who he sponsors."

I figured Luke didn't mean to call me a nobody. He just had a lot on his mind.

"You ever meet your dad?" I asked.

"Once."

I waited, thinking that if he wanted to tell me, he'd tell me. Apparently, he didn't. I wondered if the story had anything to do with how he got his scar.

Luke looked up and managed a smile. "Don't worry about it, Percy. The campers here, they're mostly good people. After all, we're extended family, right? We take care of each other."

He seemed to understand how lost I felt, and I was grateful for that, because an older guy like him—even if he was a counselor—should've steered clear of an uncool middle-schooler like me. But Luke had welcomed me into the cabin. He'd even stolen me some toiletries, which was the nicest thing anybody had done for me all day.

I decided to ask him my last big question, the one that had been bothering me all afternoon. "Clarisse, from Ares, was joking about me being 'Big Three' material. Then Annabeth ... twice, she said I might be 'the one.' She said I should talk to the Oracle. What was that all about?"

Luke folded his knife. "I hate prophecies."

"What do you mean?"

His face twitched around the scar. "Let's just say I messed things up for everybody else. The last two years, ever since my trip to the Garden of the Hesperides went sour, Chiron hasn't allowed any more quests. Annabeth's been dying to get out into the world. She pestered Chiron so much he finally told her he already knew her fate. He'd had a prophecy from the Oracle. He wouldn't tell her the whole thing, but he said Annabeth wasn't destined to go on a quest yet. She had to wait until... somebody special came to the camp."

"Somebody special?"

"Don't worry about it, kid," Luke said. "Annabeth wants to think every new camper who comes through here is the omen she's been waiting for. Now, come on, it's dinnertime."

The moment he said it, a horn blew in the distance. Somehow, I knew it was a conch shell, even though I'd never heard one before.

Luke yelled, "Eleven, fall in!"

The whole cabin, about twenty of us, filed into the commons yard. We lined up in order of seniority, so of course I was dead last. Campers came from the other cabins, too, except for the three empty cabins at the end, and cabin eight, which had looked normal in the daytime, but was now starting to glow silver as the sun went down.

We marched up the hill to the mess hall pavilion. Satyrs joined us from the meadow. Naiads emerged from the canoeing lake. A few other girls came out of the woods— and when I say out of the woods, I mean straight out of the woods. I saw one girl, about nine or ten years old, melt from the side of a maple tree and come skipping up the hill.

In all, there were maybe a hundred campers, a few dozen satyrs, and a dozen assorted wood nymphs and naiads.

At the pavilion, torches blazed around the marble columns. A central fire burned in a bronze brazier the size of a bathtub. Each cabin had its own table, covered in white cloth trimmed in purple. Four of the tables were empty, but cabin eleven's was way overcrowded. I had to squeeze on to the edge of a bench with half my butt hanging off.

I saw Grover sitting at table twelve with Mr. D, a few satyrs, and a couple of plump blond boys who looked just like Mr. D. Chiron stood to one side, the picnic table being way too small for a centaur.