Then he heard footsteps on the front porch. No-not footsteps-hooves.

"Chiron!" Drew called. "This is Jason. He's totally awesome!"

Jason backed up so fast he almost tripped. Rounding the corner of the porch was a man on horseback. Except he wasn't on horseback-he was part of the horse. From the waist up he was human, with curly brown hair and a well-trimmed beard. He wore a T-shirt that said World's Best Centaur, and had a quiver and bow strapped to his back. His head was so high up he had to duck to avoid the porch lights, because from the waist down, he was a white stallion.

Chiron started to smile at Jason. Then the color drained from his face.

"You ..." The centaur's eyes flared like a cornered animal's. "You should be dead."

Chiron ordered Jason-well, invited, but it sounded like an order-to come inside the house. He told Drew to go back to her cabin, which Drew didn't look happy about.

The centaur trotted over to the empty wheelchair on the porch. He slipped off his quiver and bow and backed up to the chair, which opened like a magician's box. Chiron gingerly stepped into it with his back legs and began scrunching himself into a s.p.a.ce that should've been much too small. Jason imagined a truck's reversing noises-beep, beep, beep-as the centaur's lower half disappeared and the chair folded up, popping out a set of fake human legs covered in a blanket, so Chiron appeared to be a regular mortal guy in a wheelchair.

"Follow me," he ordered. "We have lemonade."

The living room looked like it had been swallowed by a rain forest. Grapevines curved up the walls and across the ceiling, which Jason found a little strange. He didn't think plants grew like that inside, especially in the winter, but these were leafy green and bursting with bunches of red grapes.

Leather couches faced a stone fireplace with a crackling fire. Wedged in one corner, an old-style Pac-Man arcade game beeped and blinked. Mounted on the walls was an a.s.sortment of masks-smiley/frowny Greek theater types, feathered Mardi Gras masks, Venetian Carnevale masks with big beaklike noses, carved wooden masks from Africa. Grapevines grew through their mouths so they seemed to have leafy tongues. Some had red grapes bulging through their eyeholes.

But the weirdest thing was the stuffed leopard's head above the fireplace. It looked so real, its eyes seemed to follow Jason. Then it snarled, and Jason nearly leaped out of his skin.

"Now, Seymour," Chiron chided. "Jason is a friend. Behave yourself."

"That thing is alive!" Jason said.

Chiron rummaged through the side pocket of his wheelchair and brought out a package of Snausages. He threw one to the leopard, who snapped it up and licked his lips.

"You must excuse the decor," Chiron said. "All this was a parting gift from our old director before he was recalled to Mount Olympus. He thought it would help us to remember him. Mr. D has a strange sense of humor."

"Mr. D," Jason said. "Dionysus?"

"Mmm hmm." Chiron poured lemonade, though his hands were trembling a little. "As for Seymour, well, Mr. D liberated him from a Long Island garage sale. The leopard is Mr. D's sacred animal, you see, and Mr. D was appalled that someone would stuff such a n.o.ble creature. He decided to grant it life, on the a.s.sumption that life as a mounted head was better than no life at all. I must say it's a kinder fate than Seymour's previous owner got."

Seymour bared his fangs and sniffed the air, as if hunting for more Snausages.

"If he's only a head," Jason said, "where does the food go when he eats?"

"Better not to ask," Chiron said. "Please, sit."

Jason took some lemonade, though his stomach was fluttering. Chiron sat back in his wheelchair and tried for a smile, but Jason could tell it was forced. The old man's eyes were as deep and dark as wells.

"So, Jason," he said, "would you mind telling me-ah-where you're from?"

"I wish I knew." Jason told him the whole story, from waking up on the bus to crash-landing at Camp Half-Blood. He didn't see any point in hiding the details, and Chiron was a good listener. He didn't react to the story, other than to nod encouragingly for more.

When Jason was done, the old man sipped his lemonade.

"I see," Chiron said. "And you must have questions for me."

"Only one," Jason admitted. "What did you mean when you said that I should be dead?"

Chiron studied him with concern, as if he expected Jason to burst into flames. "My boy, do you know what those marks on your arm mean? The color of your shirt? Do you remember anything?"

Jason looked at the tattoo on his forearm: SPQR, the eagle, twelve straight lines.

"No," he said. "Nothing."

"Do you know where you are?" Chiron asked. "Do you understand what this place is, and who I am?"

"You're Chiron the centaur," Jason said. "I'm guessing you're the same one from the old stories, who used to train the Greek heroes like Heracles. This is a camp for demiG.o.ds, children of the Olympian G.o.ds."

"So you believe those G.o.ds still exist?"

"Yes," Jason said immediately. "I mean, I don't think we should worship them or sacrifice chickens to them or anything, but they're still around because they're a powerful part of civilization. They move from country to country as the center of power shifts-like they moved from Ancient Greece to Rome."

"I couldn't have said it better." Something about Chiron's voice had changed. "So you already know the G.o.ds are real. You have already been claimed, haven't you?"

"Maybe," Jason answered. "I'm not really sure."

Seymour the leopard snarled.

Chiron waited, and Jason realized what had just happened. The centaur had switched to another language and Jason had understood, automatically answering in the same tongue.

"Quis erat-" Jason faltered, then made a conscious effort to speak English. "What was that?"

"You know Latin," Chiron observed. "Most demiG.o.ds recognize a few phrases, of course. It's in their blood, but not as much as Ancient Greek. None can speak Latin fluently without practice."

Jason tried to wrap his mind around what that meant, but too many pieces were missing from his memory. He still had the feeling that he shouldn't be here. It was wrong-and dangerous. But at least Chiron wasn't threatening. In fact the centaur seemed concerned for him, afraid for his safety.

The fire reflected in Chiron's eyes, making them dance fretfully. "I taught your namesake, you know, the original Jason. He had a hard path. I've seen many heroes come and go. Occasionally, they have happy endings. Mostly, they don't. It breaks my heart, like losing a child each time one of my pupils dies. But you-you are not like any pupil I've ever taught. Your presence here could be a disaster."

"Thanks," Jason said. "You must be an inspiring teacher."

"I am sorry, my boy. But it's true. I had hoped that after Percy's success-"

"Percy Jackson, you mean. Annabeth's boyfriend, the one who's missing."

Chiron nodded. "I hoped that after he succeeded in the t.i.tan War and saved Mount Olympus, we might have some peace. I might be able to enjoy one final triumph, a happy ending, and perhaps retire quietly. I should have known better. The last chapter approaches, just as it did before. The worst is yet to come."

In the corner, the arcade game made a sad pew-pew-pew-pew sound, like a Pac-Man had just died.

"Ohh-kay," Jason said. "So-last chapter, happened before, worst yet to come. Sounds fun, but can we go back to the part where I'm supposed to be dead? I don't like that part."

"I'm afraid I can't explain, my boy. I swore on the River Styx and on all things sacred that I would never ..." Chiron frowned. "But you're here, in violation of the same oath. That too, should not be possible. I don't understand. Who would've done such a thing? Who-"

Seymour the leopard howled. His mouth froze, half open. The arcade game stopped beeping. The fire stopped crackling, its flames hardening like red gla.s.s. The masks stared down silently at Jason with their grotesque grape eyes and leafy tongues.

"Chiron?" Jason asked. "What's going-"

The old centaur had frozen, too. Jason jumped off the couch, but Chiron kept staring at the same spot, his mouth open mid-sentence. His eyes didn't blink. His chest didn't move.

Jason, a voice said.

For a horrible moment, he thought the leopard had spoken. Then dark mist boiled out of Seymour's mouth, and an even worse thought occurred to Jason: storm spirits.

He grabbed the golden coin from his pocket. With a quick flip, it changed into a sword.

The mist took the form of a woman in black robes. Her face was hooded, but her eyes glowed in the darkness. Over her shoulders she wore a goatskin cloak. Jason wasn't sure how he knew it was goatskin, but he recognized it and knew it was important.

Would you attack your patron? the woman chided. Her voice echoed in Jason's head. Lower your sword.

"Who are you?" he demanded. "How did you-"

Our time is limited, Jason. My prison grows stronger by the hour. It took me a full month to gather enough energy to work even the smallest magic through its bonds. I've managed to bring you here, but now I have little time left, and even less power. This may be the last time I can speak to you.

"You're in prison?" Jason decided maybe he wouldn't lower his sword. "Look, I don't know you, and you're not my patron."

You know me, she insisted. I have known you since your birth.

"I don't remember. I don't remember anything."

No, you don't, she agreed. That also was necessary. Long ago, your father gave me your life as a gift to placate my anger. He named you Jason, after my favorite mortal. You belong to me.

"Whoa," Jason said. "I don't belong to anyone."

Now is the time to pay your debt, she said. Find my prison. Free me, or their king will rise from the earth, and I will be destroyed. You will never retrieve your memory.

"Is that a threat? You took my memories?"

You have until sunset on the solstice, Jason. Four short days. Do not fail me.

The dark woman dissolved, and the mist curled into the leopard's mouth.

Time unfroze. Seymour's howl turned into a cough like he'd sucked in a hair ball. The fire crackled to life, the arcade machine beeped, and Chiron said, "-would dare to bring you here?"

"Probably the lady in the mist," Jason offered.

Chiron looked up in surprise. "Weren't you just sitting ... why do you have a sword drawn?"

"I hate to tell you this," Jason said, "but I think your leopard just ate a G.o.ddess."

He told Chiron about the frozen-in-time visit, the dark misty figure that disappeared into Seymour's mouth.

"Oh, dear," Chiron murmured. "That does explain a lot."

"Then why don't you explain a lot to me?" Jason said. "Please."

Before Chiron could say anything, footsteps reverberated on the porch outside. The front door blew open, and Annabeth and another girl, a redhead, burst in, dragging Piper between them. Piper's head lolled like she was unconscious.

"What happened?" Jason rushed over. "What's wrong with her?"

"Hera's cabin," Annabeth gasped, like they'd run all the way. "Vision. Bad."

The redheaded girl looked up, and Jason saw that she'd been crying.

"I think ..." The redheaded girl gulped. "I think I may have killed her."

JASON AND THE REDHEAD, WHO INTRODUCED herself as Rachel, put Piper on the couch while Annabeth rushed down the hall to get a med kit. Piper was still breathing, but she wouldn't wake up. She seemed to be in some kind of coma.

"We've got to heal her," Jason insisted. "There's a way, right?"

Seeing her so pale, barely breathing, Jason felt a surge of protectiveness. Maybe he didn't really know her. Maybe she wasn't his girlfriend. But they'd survived the Grand Canyon together. They'd come all this way. He'd left her side for a little while, and this had happened.

Chiron put his hand on her forehead and grimaced. "Her mind is in a fragile state. Rachel, what happened?"

"I wish I knew," she said. "As soon as I got to camp, I had a premonition about Hera's cabin. I went inside. Annabeth and Piper came in while I was there. We talked, and then-I just blanked out. Annabeth said I spoke in a different voice."

"A prophecy?" Chiron asked.

"No. The spirit of Delphi comes from within. I know how that feels. This was like long distance, a power trying to speak through me."

Annabeth ran in with a leather pouch. She knelt next to Piper. "Chiron, what happened back there-I've never seen anything like it. I've heard Rachel's prophecy voice. This was different. She sounded like an older woman. She grabbed Piper's shoulders and told her-"

"To free her from a prison?" Jason guessed.

Annabeth stared at him. "How did you know that?"

Chiron made a three-fingered gesture over his heart, like a ward against evil.

"Jason, tell them. Annabeth, the medicine bag, please."

Chiron trickled drops from a medicine vial into Piper's mouth while Jason explained what had happened when the room froze-the dark misty woman who had claimed to be Jason's patron.

When he was done, no one spoke, which made him more anxious.

"So does this happen often?" he asked. "Supernatural phone calls from convicts demanding you bust them out of jail?"

"Your patron," Annabeth said. "Not your G.o.dly parent?"

"No, she said patron. She also said my dad had given her my life."

Annabeth frowned. "I've never of heard anything like that before. You said the storm spirit on the skywalk-he claimed to be working for some mistress who was giving him orders, right? Could it be this woman you saw, messing with your mind?"

"I don't think so," Jason said. "If she were my enemy, why would she be asking for my help? She's imprisoned. She's worried about some enemy getting more powerful. Something about a king rising from the earth on the solstice-"

Annabeth turned to Chiron. "Not Kronos. Please tell me it's not that."

The centaur looked miserable. He held Piper's wrist, checking her pulse.