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."

"But I'm just a kid!"

"Percy," Grover cut in, "if you were Zeus, and you already thought your brother was plotting to overthrow you, then your brother suddenly admitted he had broken the sacred oath he took after World War II, that he's fathered a new mortal hero who might be used as a weapon against you…. Wouldn't that put a twist in your toga?"

"But I didn't do anything. Poseidon—my dad—he didn't really have this master bolt stolen, did he?"

Chiron sighed. "Most thinking observers would agree that thievery is not Poseidon's style. But the Sea God is too proud to try convincing Zeus of that. Zeus has demanded that Poseidon return the bolt by the summer solstice. That's June twenty-first, ten days from now. Poseidon wants an apology for being called a thief by the same date. I hoped that diplomacy might prevail, that Hera or Demeter or Hestia would make the two brothers see sense. But your arrival has inflamed Zeus's temper. Now neither god will back down. Unless someone intervenes, unless the master bolt is found and returned to Zeus before the solstice, there will be war. And do you know what a full-fledged war would look like, Percy?"

"Bad?" I guessed.

"Imagine the world in chaos. Nature at war with itself. Olympians forced to choose sides between Zeus and Poseidon. Destruction. Carnage. Millions dead. Western civilization turned into a battleground so big it will make the Trojan War look like a water-balloon fight."

"Bad," I repeated.

"And you, Percy Jackson, would be the first to feel Zeus's wrath."

It started to rain. Volleyball players stopped their game and stared in stunned silence at the sky.

I had brought this storm to Half-Blood Hill. Zeus was punishing the whole camp because of me. I was furious.

"So I have to find the stupid bolt," I said. "And return it to Zeus."

"What better peace offering," Chiron said, "than to have the son of Poseidon return Zeus's property?"

"If Poseidon doesn't have it, where is the thing?"

"I believe I know." Chiron's expression was grim. "Part of a prophecy I had years ago… well, some of the lines make sense to me, now. But before I can say more, you must officially take up the quest. You must seek the counsel of the Oracle."

"Why can't you tell me where the bolt is beforehand?"

"Because if I did, you would be too afraid to accept the challenge."

I swallowed. "Good reason."

"You agree then?"

I looked at Grover, who nodded encouragingly.

Easy for him. I was the one Zeus wanted to kill.

"All right," I said. "It's better than being turned into a dolphin."

"Then it's time you consulted the Oracle," Chiron said. "Go upstairs, Percy Jackson, to the attic. When you come back down, assuming you're still sane, we will talk more."