“You’ve met her before?”

“Um, last winter. But seriously, I barely know her.”

“She’s kind of cute.”

“I—I never thought about it.”

Annabeth kept walking toward York Avenue.

“I’ll deal with the school,” I promised, anxious to change the subject. “Honest, it’ll be fine.”

Annabeth wouldn’t even look at me. “I guess our afternoon is off. We should get you out of here, now that the police will be searching for you.”

Behind us, smoke billowed up from Goode High School. In the dark column of ashes, I thought I could almost see a face—a she-demon with red eyes, laughing at me.

Your pretty little camp in flames, Kelli had said. Your friends made slaves to the Lord of Time.

“You’re right,” I told Annabeth, my heart sinking. “We have to get to Camp Half-Blood. Now.”

TWO

THE UNDERWORLD SENDS

ME A PRANK CALL

Nothing caps off the perfect morning like a long taxi ride with an angry girl.

I tried to talk to Annabeth, but she was acting like I’d just punched her grandmother. All I managed to get out of her was that she’d had a monster-infested spring in San Francisco; she’d come back to camp twice since Christmas but wouldn’t tell me why (which kind of ticked me off, because she hadn’t even told me she was in New York); and she’d learned nothing about the whereabouts of Nico di Angelo (long story).

“Any word on Luke?” I asked.

She shook her head. I knew this was a touchy subject for her. Annabeth had always admired Luke, the former head counselor for Hermes who had betrayed us and joined the evil Titan Lord Kronos. She wouldn’t admit it, but I knew she still liked him. When we’d fought Luke on Mount Tamalpais last winter, he’d somehow survived a fifty-foot fall off a cliff. Now, as far as I knew, he was still sailing around on his demon-infested cruise ship while his chopped-up Lord Kronos re-formed, bit by bit, in a golden sarcophagus, biding his time until he had enough power to challenge the Olympian gods. In demigod-speak, we call this a “problem.”

“Mount Tam is still overrun with monsters,” Annabeth said. “I didn’t dare go close, but I don’t think Luke is up there. I think I would know if he was.”

That didn’t make me feel much better. “What about Grover?”

“He’s at camp,” she said. “We’ll see him today.”

“Did he have any luck? I mean, with the search for Pan?”

Annabeth fingered her bead necklace, the way she does when she’s worried.

“You’ll see,” she said. But she didn’t explain.

As we headed through Brooklyn, I used Annabeth’s phone to call my mom. Half-bloods try not to use cell phones if we can avoid it, because broadcasting our voices is like sending up a flare to the monsters: Here I am! Please eat me now! But I figured this call was important. I left a message on our home voice mail, trying to explain what had happened at Goode. I probably didn’t do a very good job. I told my mom I was fine, she shouldn’t worry, but I was going to stay at camp until things cooled down. I asked her to tell Paul Blofis I was sorry.

We rode in silence after that. The city melted away until we were off the expressway and rolling through the countryside of northern Long Island, past orchards and wineries and fresh produce stands.

I stared at the phone number Rachel Elizabeth Dare had scrawled on my hand. I knew it was crazy, but I was tempted to call her. Maybe she could help me understand what the empousa had been talking about—the camp burning, my friends imprisoned. And why had Kelli exploded into flames?

I knew monsters never truly died. Eventually—maybe weeks, months, or years from now—Kelli would re-form out of the primordial nastiness seething in the Underworld. But still, monsters didn’t usually let themselves get destroyed so easily. If she really was destroyed.

The taxi exited on Route 25A. We headed through the woods along the North Shore until a low ridge of hills appeared on our left. Annabeth told the driver to pull over on Farm Road 3.141, at the base of Half-Blood Hill.

The driver frowned. “There ain’t nothing here, miss. You sure you want out?”

“Yes, please,” Annabeth handed him a roll of mortal cash, and the driver decided not to argue.

Annabeth and I hiked to the crest of the hill. The young guardian dragon was dozing, coiled around the pine tree, but he lifted his coppery head as we approached and let Annabeth scratch under his chin. Steam hissed out his nostrils like from a teakettle, and he went cross-eyed with pleasure.

“Hey, Peleus,” Annabeth said. “Keeping everything safe?”

The last time I’d seen the dragon he’d been six feet long. Now he was at least twice that, and as thick around as the tree itself. Above his head, on the lowest branch of the pine tree, the Golden Fleece shimmered, its magic protecting the camp’s borders from invasion. The dragon seemed relaxed, like everything was okay. Below us, Camp Half-Blood looked peaceful— green fields, forest, shiny white Greek buildings. The four-story farmhouse we called the Big House sat proudly in the midst of the strawberry fields. To the north, past the beach, the Long Island Sound glittered in the sunlight.

Still…something felt wrong. There was tension in the air, as if the hill itself were holding its breath, waiting for something bad to happen.

We walked down into the valley and found the summer session in full swing. Most of the campers had arrived last Friday, so I already felt out of it. The satyrs were playing their pipes in the strawberry fields, making the plants grow with woodland magic. Campers were having flying horseback lessons, swooping over the woods on their pegasi. Smoke rose from the forges, and hammers rang as kids made their own weapons for Arts & Crafts. The Athena and Demeter teams were having a chariot race around the track, and over at the canoe lake some kids in a Greek trireme were fighting a large orange sea serpent. A typical day at camp.

“I need to talk to Clarisse,” Annabeth said.

I stared at her as if she’d just said I need to eat a large, smelly boot. “What for?”

Clarisse from the Ares cabin was one of my least favorite people. She was a mean, ungrateful bully. Her dad, the war god, wanted to kill me. She tried to beat me to a pulp on a regular basis. Other than that, she was just great.

“We’ve been working on something,” Annabeth said. “I’ll see you later.”

“Working on what?”

Annabeth glanced toward the forest.

“I’ll tell Chiron you’re here,” she said. “He’ll want to talk to you before the hearing.”

“What hearing?”

But she jogged down the path toward the archery field without looking back.

“Yeah,” I muttered. “Great talking with you, too.”

***

As I made my way through camp, I said hi to some of my friends. In the Big House’s driveway, Connor and Travis Stoll from the Hermes cabin were hot-wiring the camps SUV. Silena Beauregard, the head counselor for Aphrodite, waved at me from her Pegasus as she flew past. I looked for Grover, but I didn’t see him. Finally I wandered into the sword arena, where I usually go when I’m in a bad mood. Practicing always calms me down. Maybe that’s because swordplay is one thing I can actually understand.

I walked into the amphitheater and my heart almost stopped. In the middle of the arena floor, with its back to me, was the biggest hellhound I’d ever seen.

I mean, I’ve seen some pretty big hellhounds. One the size of a rhino tried to kill me when I was twelve. But this hellhound was bigger than a tank. I had no idea how it had gotten past the camp’s magic boundaries. It looked right at home, lying on its belly, growling contentedly as it chewed the head off a combat dummy. It hadn’t noticed me yet, but if I made a sound, I knew it would sense me. There was no time to go for help. I pulled out Riptide and uncapped it.

“Yaaaaah!” I charged. I brought down the blade on the monster’s enormous backside when out of nowhere another sword blocked my strike.

CLANG!

The hellhound pricked up its ears. “WOOF!”

I jumped back and instinctively struck at the swordsman—a gray-haired man in Greek armor. He parried my attack with no problem.

“Whoa there!” he said. “Truce!”

“WOOF!” The hellhound’s bark shook the arena.

“That’s a hellhound!” I shouted.

“She’s harmless,” the man said. “That’s Mrs. O’Leary.”

I blinked. “Mrs. O’Leary?”

At the sound of her name, the hellhound barked again. I realized she wasn’t angry. She was excited. She nudged the soggy, badly chewed target dummy toward the swordsman.

“Good girl,” the man said. With his free hand he grabbed the armored manikin by the neck and heaved it toward the bleachers. “Get the Greek! Get the Greek!”

Mrs. O’Leary bounded after her prey and pounced on the dummy, flattening its armor. She began chewing on its helmet.

The swordsman smiled dryly. He was in his fifties. I guess, with short gray hair and a clipped gray beard. He was in good shape for an older guy. He wore black mountain-climbing pants and a bronze breastplate strapped over an orange camp T-shirt. At the base of his neck was a strange mark, a purplish blotch like a birthmark or a tattoo, but before I could make out what it was, he shifted his armor straps and the mark disappeared under his collar.

“Mrs. O’Leary is my pet,” he explained. “I couldn’t let you stick a sword in her rump, now, could I? That might have scared her.”

“Who are you?”

Promise not to kill me if I put my sword away?”

“I guess.”

He sheathed his sword and held out his hand. “Quintus.”

I shook his hand. It was as rough as a sandpaper.

“Percy Jackson,” I said. “Sorry about—How did you, um—”

“Get a hellhound for a pet? Long story, involving many close calls with a death and quite a few giant chew toys. I’m the new sword instructor, by the way. Helping out Chiron while Mr. D is away.”

“Oh.” I tried not to stare as Mrs. O’Leary ripped off the target dummy’s shield with the arm still attached and shook it like a Frisbee. “Wait, Mr. D is away?”

“Yes, well…busy times. Even Dionysus must help out. He’s gone to visit some old friends. Make sure they’re on the right side. I probably shouldn’t say more than that.”

If Dionysus was gone, that was the best news I’d had all day. He was only our camp director because Zeus had sent him here as a punishment for chasing some off-limits wood nymph. He hated the campers and tried to make our lives miserable. With him away, this summer might actually be cool. On the other hand, if Dionysus had gotten off his butt and actually started helping the gods recruit against the Titan threat, things must be looking pretty bad.

Off to my left, there was a loud BUMP. Six wooden crates the size of picnic tables were stacked nearby, and they were rattling. Mrs. O’Leary cocked her head and bounded toward them.