The Sea of Monsters

camp was in danger. The magical borders were failing because Thalia’s tree was dying.
    Someone had poisoned it.

FIVE

I GET A NEW CABIN MATE
    Ever come home and found your room messed up? Like some helpful person (hi, Mom) has tried to “clean” it, and suddenly you can’t find anything? And even if nothing is missing, you get that creepy feeling like somebody’s been looking through your private stuff and dusting everything with lemon furniture polish?
    That’s kind of the way I felt seeing Camp Half-Blood again.
    On the surface, things didn’t look all that different. The Big House was still there with its blue gabled roof and its wraparound porch. The strawberry fields still baked in the sun. The same white-columned Greek buildings were scattered around the valley—the amphitheater, the combat arena, the dining pavilion overlooking Long Island Sound. And nestled between the woods and the creek were the same cabins—a crazy assortment of twelve buildings, each representing a different Olympian god.
    But there was an air of danger now. You could tell something was wrong. Instead of playing volleyball in the sandpit, counselors and satyrs were stockpiling weapons in the tool shed. Dryads armed with bows and arrows talked nervously at the edge of the woods. The forest looked sickly, the grass in the meadow was pale yellow, and the fire marks on Half-Blood Hill stood out like ugly scars.
    Somebody had messed with my favorite place in the world, and I was not . . . well, a happy camper.
    As we made our way to the Big House, I recognized a lot of kids from last summer. Nobody stopped to talk. Nobody said, “Welcome back.” Some did double takes when they saw Tyson, but most just walked grimly past and carried on with their duties—running messages, toting swords to sharpen on the grinding wheels. The camp felt like a military school. And believe me, I know. I’ve been kicked out of a couple.
    None of that mattered to Tyson. He was absolutely fascinated by everything he saw. “Whasthat!” he gasped.
    “The stables for pegasi,” I said. “The winged horses.”
    “Whasthat!”
    “Um . . . those are the toilets.”
    “Whasthat!”
    “The cabins for the campers. If they don’t know who your Olympian parent is, they put you in the Hermes cabin—that brown one over there—until you’re determined. Then, once they know, they put you in your dad or mom’s group.”
    He looked at me in awe. “You . . . have a cabin ?”
    “Number three.” I pointed to a low gray building made of sea stone.
    “You live with friends in the cabin?”
    “No. No, just me.” I didn’t feel like explaining. The embarrassing truth: I was the only one who stayed in that cabin because I wasn’t supposed to be alive. The “Big Three” gods—Zeus, Poseidon, and Hades—had made a pact after World War II not to have any more children with mortals. We were more powerful than regular half-bloods. We were too unpredictable. When we got mad we tended to cause problems . . . like World War II, for instance. The “Big Three” pact had only been broken twice—once when Zeus sired Thalia, once when Poseidon sired me. Neither of us should’ve been born.
    Thalia had gotten herself turned into a pine tree when she was twelve. Me . . . well, I was doing my best not to follow her example. I had nightmares about what Poseidon might turn me into if I were ever on the verge of death— plankton, maybe. Or a floating patch of kelp.
    When we got to the Big House, we found Chiron in his apartment, listening to his favorite 1960s lounge music while he packed his saddlebags. I guess I should mention— Chiron is a centaur. From the waist up he looks like a regular middle-aged guy with curly brown hair and a scraggly beard. From the waist down, he’s a white stallion. He can pass for human by compacting his lower half into a magic wheelchair. In fact, he’d passed himself off as my Latin teacher during my sixth-grade year. But most of the time, if the ceilings are high enough, he prefers hanging out in full centaur form.
    As soon as we saw him, Tyson froze. “Pony!” he cried in total rapture.
    Chiron turned, looking offended. “I beg your pardon?”
    Annabeth ran up and hugged him. “Chiron, what’s happening? You’re not . . . leaving?” Her voice was shaky. Chiron was like a second father to her.
    Chiron ruffled her hair and gave her a kindly smile. “Hello, child. And Percy, my goodness. You’ve grown over the year!”
    I