"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."

Four flights up, the stairs ended under a green trapdoor.

I pulled the cord. The door swung down, and a wooden ladder clattered into place.

The warm air from above smelled like mildew and rotten wood and something else ... a smell I remembered from biology class. Reptiles. The smell of snakes.

I held my breath and climbed.

The attic was filled with Greek hero junk: armor stands covered in cobwebs; once-bright shields pitted with rust; old leather steamer trunks plastered with stickers saying ITHAKA, CIRCE'S ISLE, and LAND OF THE AMAZONS. One long table was stacked with glass jars filled with pickled things—severed hairy claws, huge yellow eyes, various other parts of monsters. A dusty mounted trophy on the wall looked like a giant snake's head, but with horns and a full set of shark's teeth. The plaque read, HYDRA HEAD #1, WOODSTOCK, N.Y., 1969.

By the window, sitting on a wooden tripod stool, was the most gruesome memento of all: a mummy. Not the wrapped-in-cloth kind, but a human female body shriveled to a husk. She wore a tie-dyed sundress, lots of beaded necklaces, and a headband over long black hair. The skin of her face was thin and leathery over her skull, and her eyes were glassy white slits, as if the real eyes had been replaced by marbles; she'd been dead a long, long time.

Looking at her sent chills up my back. And that was before she sat up on her stool and opened her mouth. A green mist poured from the mummy's mouth, coiling over the floor in thick tendrils, hissing like twenty thousand snakes. I stumbled over myself trying to get to the trapdoor, but it slammed shut. Inside my head, I heard a voice, slithering into one ear and coiling around my brain: I am the spirit of Delphi, speaker of the prophecies of Phoebus Apollo, slayer of the mighty Python. Approach, seeker, and ask.

I wanted to say, No thanks, wrong door, just looking for the bathroom. But I forced myself to take a deep breath.

The mummy wasn't alive. She was some kind of gruesome receptacle for something else, the power that was now swirling around me in the green mist. But its presence didn't feel evil, like my demonic math teacher Mrs. Dodds or the Minotaur. It felt more like the Three Fates I'd seen knitting the yarn outside the highway fruit stand: ancient, powerful, and definitely not human. But not particularly interested in killing me, either.

I got up the courage to ask, "What is my destiny?"

The mist swirled more thickly, collecting right in front of me and around the table with the pickled monster-part jars. Suddenly there were four men sitting around the table, playing cards. Their faces became clearer. It was Smelly Gabe and his buddies.

My fists clenched, though I knew this poker party couldn't be real. It was an illusion, made out of mist.

Gabe turned toward me and spoke in the rasping voice of the Oracle: You shall go west, and face the god who has turned.

His buddy on the right looked up and said in the same voice: You shall find what was stolen, and see it safely returned.

The guy on the left threw in two poker chips, then said: You shall be betrayed by one who calls you a friend.

Finally, Eddie, our building super, delivered the worst line of all: And you shall fail to save what matters most, in the end.

The figures began to dissolve. At first I was too stunned to say anything, but as the mist retreated, coiling into a huge green serpent and slithering back into the mouth of the mummy, I cried, "Wait! What do you mean? What friend? What will I fail to save?"

The tail of the mist snake disappeared into the mummy's mouth. She reclined back against the wall. Her mouth closed tight, as if it hadn't been open in a hundred years. The attic was silent again, abandoned, nothing but a room full of mementos.

I got the feeling that I could stand here until I had cobwebs, too, and I wouldn't learn anything else.

My audience with the Oracle was over.

"Well?" Chiron asked me.

I slumped into a chair at the pinochle table. "She said I would retrieve what was stolen."

Grover sat forward, chewing excitedly on the remains of a Diet Coke can. "That's great!"

"What did the Oracle say exactly?" Chiron pressed. "This is important."

My ears were still tingling from the reptilian voice. "She . .. she said I would go west and face a god who had turned. I would retrieve what was stolen and see it safely returned."

"I knew it," Grover said.. . .. 

Chiron didn't look satisfied. "Anything else?"

I didn't want to tell him.

What friend would betray me? I didn't have that many.

And the last line—I would fail to save what mattered most. What kind of Oracle would send me on a quest and tell me, Oh, by the way, you'll fail

How could I confess that?

"No," I said. "That's about it."

He studied my face. "Very well, Percy. But know this: the Oracle's words often have double meanings. Don't dwell on them too much. The truth is not always clear until events come to pass."

I got the feeling he knew I was holding back something bad, and he was trying to make me feel better.

"Okay," I said, anxious to change topics. "So where do I go? Who's this god in the west?"

"Ah, think, Percy," Chiron said. "If Zeus and Poseidon weaken each other in a war, who stands to gain?"

"Somebody else who wants to take over?" I guessed.

"Yes, quite. Someone who harbors a grudge, who has been unhappy with his lot since the world was divided eons ago, whose kingdom would grow powerful with the deaths of millions. Someone who hates his brothers for forcing him into an oath to have no more children, an oath that both of them have now broken."

I thought about my dreams, the evil voice that had spoken from under the ground. "Hades."

Chiron nodded. "The Lord of the Dead is the only possibility."

A scrap of aluminum dribbled out of Grover's mouth. "Whoa, wait. Wh-what?"

"A Fury came after Percy," Chiron reminded him. "She watched the young man until she was sure of his identity, then tried to kill him. Furies obey only one lord: Hades."

"Yes, but—but Hades hates all heroes," Grover protested. "Especially if he has found out Percy is a son of Poseidon... ."

"A hellhound got into the forest," Chiron continued. "Those can only be summoned from the Fields of Punishment, and it had to be summoned by someone within the camp. Hades must have a spy here. He must suspect Poseidon will try to use Percy to clear his name. Hades would very much like to kill this young half-blood before he can take on the quest."

"Great," I muttered. "That's two major gods who want to kill me."

"But a quest to ..." Grover swallowed. "I mean, couldn't the master bolt be in some place like Maine? Maine's very nice this time of year."

"Hades sent a minion to steal the master bolt," Chiron insisted. "He hid it in the Underworld, knowing full well that Zeus would blame Poseidon. I don't pretend to understand the Lord of the Dead's motives perfectly, or why he chose this time to start a war, but one thing is certain. Percy must go to the Underworld, find the master bolt, and reveal the truth."  

A strange fire burned in my stomach. The weirdest thing was: it wasn't fear. It was anticipation. The desire for revenge. Hades had tried to kill me three times so far, with the Fury, the Minotaur, and the hellhound. It was his fault my mother had disappeared in a flash of light. Now he was trying to frame me and my dad for a theft we hadn't committed.

I was ready to take him on.

Besides, if my mother was in the Underworld ...

Whoa, boy, said the small part of my brain that was still sane. You're a kid. Hades is a god.

Grover was trembling. He'd started eating pinochle cards like potato chips.

The poor guy needed to complete a quest with me so he could get his searcher's license, whatever that was, but how could I ask him to do this quest, especially when the Oracle said I was destined to fail? This was suicide.

"Look, if we know it's Hades," I told Chiron, "why can't we just tell the other gods? Zeus or Poseidon could go down to the Underworld and bust some heads."

"Suspecting and knowing are not the same," Chiron said. "Besides, even if the other gods suspect Hades—and I imagine Poseidon does—they couldn't retrieve the bolt themselves. Gods cannot cross each other's territories except by invitation. That is another ancient rule. Heroes, on the other hand, have certain privileges. They can go anywhere, challenge anyone, as long as they're bold enough and strong enough to do it. No god can be held responsible for a hero's actions. Why do you think the gods always operate through humans?"