Mother and son had gone for a weekend vacation to Montauk, but left hastily, under mysterious circumstances. Small traces of blood were found in the car and near the scene of the wreck, but there were no other signs of the missing Jacksons. Residents in the rural area reported seeing nothing unusual around the time of the accident.

Ms. Jackson's husband, Gabe Ugliano, claims that his stepson, Percy Jackson, is a troubled child who has been kicked out of numerous boarding schools and has expressed violent tendencies in the past.

Police would not say whether son Percy is a suspect in his mother's disappearance, but they have not ruled out foul play. Below are recent pictures of Sally Jackson and Percy. Police urge anyone with information to call the following toll-free crime-stoppers hotline.

The phone number was circled in black marker.

I wadded up the paper and threw it away, then flopped down in my bunk bed in the middle of my empty cabin.

"Lights out," I told myself miserably.

That night, I had my worst dream yet.

I was running along the beach in a storm. This time, there was a city behind me. Not New York. The sprawl was different: buildings spread farther apart, palm trees and low hills in the distance.

About a hundred yards down the surf, two men were fighting. They looked like TV wrestlers, muscular, with beards and long hair. Both wore flowing Greek tunics, one trimmed in blue, the other in green. They grappled with each other, wrestled, kicked and head-butted, and every time they connected, lightning flashed, the sky grew darker, and the wind rose.

I had to stop them. I didn't know why. But the harder I ran, the more the wind blew me back, until I was running in place, my heels digging uselessly in the sand.

Over the roar of the storm, I could hear the blue-robed one yelling at the green-robed one, Give it back! Give it back! Like a kindergartner fighting over a toy.

The waves got bigger, crashing into the beach, spraying me with salt.

I yelled, Stop it! Stop fighting!

The ground shook. Laughter came from somewhere under the earth, and a voice so deep and evil it turned my blood to ice.

Come down, little hero, the voice crooned. Come down!

The sand split beneath me, opening up a crevice straight down to the center of the earth. My feet slipped, and darkness swallowed me.

I woke up, sure I was falling.

I was still in bed in cabin three. My body told me it was morning, but it was dark outside, and thunder rolled across the hills. A storm was brewing. I hadn't dreamed that.

I heard a clopping sound at the door, a hoof knocking on the threshold.

"Come in?"

Grover trotted inside, looking worried. "Mr. D wants to see you."

"Why?"

"He wants to kill... I mean, I'd better let him tell you."

Nervously, I got dressed and followed, sure that I was in huge trouble.

For days, I'd been half expecting a summons to the Big House. Now that I was declared a son of Poseidon, one of the Big Three gods who weren't supposed to have kids, I figured it was a crime for me just to be alive. The other gods had probably been debating the best way to punish me for existing, and now Mr. D was ready to deliver their verdict.

Over Long Island Sound, the sky looked like ink soup coming to a boil. A hazy curtain of rain was coming in our direction. I asked Grover if we needed an umbrella.

"No," he said. "It never rains here unless we want it to."

I pointed at the storm. "What the heck is that, then?"

He glanced uneasily at the sky. "It'll pass around us. Bad weather always does."

I realized he was right. In the week I'd been here, it had never even been overcast. The few rain clouds I'd seen had skirted right around the edges of the valley.

But this storm ... this one was huge.

At the volleyball pit, the kids from Apollo's cabin were playing a morning game against the satyrs. Dionysus's twins were walking around in the strawberry fields, making the plants grow. Everybody was going about their normal business, but they looked tense. They kept their eyes on the storm.

Grover and I walked up to the front porch of the Big House. Dionysus sat at the pinochle table in his tiger-striped Hawaiian shirt with his Diet Coke, just as he had on my first day. Chiron sat across the table in his fake wheelchair. They were playing against invisible opponents--two sets of cards hovering in the air.

"Well, well," Mr. D said without looking up. "Our little celebrity."

I waited.. . . . . . . . . 

"Come closer," Mr. D said. "And don't expect me to kowtow to you, mortal, just because old Barnacle-Beard is your father."

A net of lightning flashed across the clouds. Thunder shook the windows of the house.

"Blah, blah, blah," Dionysus said.

Chiron feigned interest in his pinochle cards. Grover cowered by the railing, his hooves clopping back and forth.

"If I had my way," Dionysus said, "I would cause your molecules to erupt in flames. We'd sweep up the ashes and be done with a lot of trouble. But Chiron seems to feel this would be against my mission at this cursed camp: to keep you little brats safe from harm."

"Spontaneous combustion is a form of harm, Mr. D," Chiron put in.

"Nonsense," Dionysus said. "Boy wouldn't feel a thing. Nevertheless, I've agreed to restrain myself I'm thinking of turning you into a dolphin instead, sending you back to your father."

"Mr. D—" Chiron warned.

"Oh, all right," Dionysus relented. "There's one more option. But it's deadly foolishness." Dionysus rose, and the invisible players' cards dropped to the table. "I'm off to Olympus for the emergency meeting. If the boy is still here when I get back, I'll turn him into an Atlantic bottlenose. Do you understand? And Perseus Jackson, if you're at all smart, you'll see that's a much more sensible choice than what Chiron feels you must do."

Dionysus picked up a playing card, twisted it, and it became a plastic rectangle. A credit card? No. A security pass.

He snapped his fingers.

The air seemed to fold and bend around him. He became a hologram, then a wind, then he was gone, leaving only the smell of fresh-pressed grapes lingering behind.

Chiron smiled at me, but he looked tired and strained. "Sit, Percy, please. And Grover."

We did.

Chiron laid his cards on the table, a winning hand he hadn't gotten to use.

"Tell me, Percy," he said. "What did you make of the hellhound?"

Just hearing the name made me shudder.

Chiron probably wanted me to say, Heck, it was nothing. I eat hellhounds for breakfast. But I didn't feel like lying.

"It scared me," I said. "If you hadn't shot it, I'd be dead."

"You'll meet worse, Percy. Far worse, before you're done."

"Done ... with what?"

"Your quest, of course. Will you accept it?"

I glanced at Grover, who was crossing his fingers.

"Um, sir," I said, "you haven't told me what it is yet."

Chiron grimaced. "Well, that's the hard part, the details."

Thunder rumbled across the valley. The storm clouds had now reached the edge of the beach. As far as I could see, the sky and the sea were boiling together.

"Poseidon and Zeus," I said. "They're fighting over something valuable ... something that was stolen, aren't they?".

Chiron and Grover exchanged looks.

Chiron sat forward in his wheelchair. "How did you know that?"

My face felt hot. I wished I hadn't opened my big mouth. "The weather since Christmas has been weird, like the sea and the sky are fighting. Then I talked to Annabeth, and she'd overheard something about a theft. And ... I've also been having these dreams."

"I knew it," Grover said.

"Hush, satyr," Chiron ordered.

"But it is his quest!" Grover's eyes were bright with excitement. "It must be!"

"Only the Oracle can determine." Chiron stroked his bristly beard. "Nevertheless, Percy, you are correct. Your father and Zeus are having their worst quarrel in centuries. They are fighting over something valuable that was stolen. To be precise: a lightning bolt."

I laughed nervously. "A what?"

"Do not take this lightly," Chiron warned. "I'm not talking about some tinfoil-covered zigzag you'd see in a second-grade play. I'm talking about a two-foot-long cylinder of high-grade celestial bronze, capped on both ends with god-level explosives."

"Oh."

"Zeus's master bolt," Chiron said, getting worked up now. "The symbol of his power, from which all other lightning bolts are patterned. The first weapon made by the Cyclopes for the war against the Titans, the bolt that sheered the top off Mount Etna and hurled Kronos from his throne; the master bolt, which packs enough power to make mortal hydrogen bombs look like firecrackers."

"And it's missing?"

"Stolen," Chiron said.

"By who?"

"By whom," Chiron corrected. Once a teacher, always a teacher. "By you."

My mouth fell open.

"At least"—Chiron held up a hand—"that's what Zeus thinks. During the winter solstice, at the last council of the gods, Zeus and Poseidon had an argument. The usual nonsense: 'Mother Rhea always liked you best', 'Air disasters are more spectacular than sea disasters,' et cetera. Afterward, Zeus realized his master bolt was missing, taken from the throne room under his very nose. He immediately blamed Poseidon. Now, a god cannot usurp another god's symbol of power directly—that is forbidden by the most ancient of divine laws. But Zeus believes your father convinced a human hero to take it."

"But I didn't—"

"Patience and listen, child," Chiron said. "Zeus has good reason to be suspicious. The forges of the Cyclopes are under the ocean, which gives Poseidon some influence over the makers of his brother's lightning. Zeus believes Poseidon has taken the master bolt, and is now secretly having the Cyclopes build an arsenal of illegal copies, which might be used to topple Zeus from his throne. The only thing Zeus wasn't sure about was which hero Poseidon used to steal the bolt. Now Poseidon has openly claimed you as his son. You were in New York over the winter holidays. You could easily have snuck into Olympus. Zeus believes he has found his thief."

"But I've never even been to Olympus! Zeus is crazy!"

Chiron and Grover glanced nervously at the sky. The clouds didn't seem to be parting around us, as Grover had promised. They were rolling straight over our valley, sealing us in like a coffin lid.

"Er, Percy ...?" Grover said. "We don't use the c-word to describe the Lord of the Sky."

"Perhaps paranoid," Chiron suggested. "Then again, Poseidon has tried to unseat Zeus before. I believe that was question thirty-eight on your final exam...." He looked at me as if he actually expected me to remember question thirty-eight.

How could anyone accuse me of stealing a god's weapon? I couldn't even steal a slice of pizza from Gabe's poker party without getting busted. Chiron was waiting for an answer.

"Something about a golden net?" I guessed. "Poseidon and Hera and a few other gods ... they, like, trapped Zeus and wouldn't let him out until he promised to be a better ruler, right?"

"Correct," Chiron said. "And Zeus has never trusted Poseidon since. Of course, Poseidon denies stealing the master bolt. He took great offense at the accusation. The two have been arguing back and forth for months, threatening war. And now, you've come along—the proverbial last straw."