“For now?” he asked.

Hera gestured at the tendrils of her cage. “There are worse trials to come. The very earth stirs against us.”

“You’re a goddess,” Jason said. “Why can’t you just escape?”

Hera smiled sadly. Her form began to glow, until her brilliance filled the cage with painful light. The air hummed with power, molecules splitting apart like a nuclear explosion. Jason suspected if he were actually there in the flesh, he would’ve been vaporized.

The cage should’ve been blasted to rubble. The ground should’ve split and the ruined house should’ve been leveled. But when the glow died, the cage hadn’t budged. Nothing outside the bars had changed. Only Hera looked different—a little more stooped and tired.

“Some powers are even greater than the gods,” she said. “I am not easily contained. I can be in many places at once. But when the greater part of my essence is caught, it is like a foot in a bear trap, you might say. I can’t escape, and I am concealed from the eyes of the other gods. Only you can find me, and I grow weaker by the day.”

“Then why did you come here?” Jason asked. “How were you caught?”

The goddess sighed. “I could not stay idle. Your father Jupiter believes he can withdraw from the world, and thus lull our enemies back to sleep. He believes we Olympians have become too involved in the affairs of mortals, in the fates of our demigod children, especially since we agreed to claim them all after the war. He believes this is what has caused our enemies to stir. That is why he closed Olympus.”

“But you don’t agree.”

“No,” she said. “Often I do not understand my husband’s moods or his decisions, but even for Zeus, this seemed paranoid. I cannot fathom why he was so insistent and so convinced. It was … unlike him. As Hera, I might have been content to follow my lord’s wishes. But I am also Juno.” Her image flickered, and Jason saw armor under her simple black robes, a goatskin cloak—the symbol of a Roman warrior—across her bronze mantle. “Juno Moneta they once called me—Juno, the One Who Warns. I was guardian of the state, patron of Eternal Rome. I could not sit by while the descendants of my people were attacked. I sensed danger at this sacred spot. A voice—” She hesitated. “A voice told me I should come here. Gods do not have what you might call a conscience, nor do we have dreams; but the voice was like that—soft and persistent, warning me to come here. And so the same day Zeus closed Olympus, I slipped away without telling him my plans, so he could not stop me. And I came here to investigate.”

“It was a trap,” Jason guessed.

The goddess nodded. “Only too late did I realize how quickly the earth was stirring. I was even more foolish than Jupiter—a slave to my own impulses. This is exactly how it happened the first time. I was taken captive by the giants, and my imprisonment started a war. Now our enemies rise again. The gods can only defeat them with the help of the greatest living heroes. And the one whom the giants serve …she cannot be defeated at all—only kept asleep.”

“I don’t understand.”

“You will soon,” Hera said.

The cage began to constrict, the tendrils spiraling tighter. Hera’s form shivered like a candle flame in the breeze. Outside the cage, Jason could see shapes gathering at the edge of the pool—lumbering humanoids with hunched backs and bald heads. Unless Jason’s eyes were tricking him—they had more than one set of arms. He heard wolves too, but not the wolves he’d seen with Lupa. He could tell from their howls this was a different pack—hungrier, more aggressive, out for blood.

“Hurry, Jason,” Hera said. “My keepers approach, and you begin to wake. I will not be strong enough to appear to you again, even in dreams.”

“Wait,” he said. “Boreas told us you’d made a dangerous gamble. What did he mean?”

Hera’s eyes looked wild, and Jason wondered if she really had done something crazy.

“An exchange,” she said. “The only way to bring peace. The enemy counts on our divisions, and if we are divided, we will be destroyed. You are my peace offering, Jason—a bridge to overcome millennia of hatred.”

“What? I don’t—”

“I cannot tell you more,” Hera said. “You have only lived this long because I have taken your memory. Find this place.

Return to your starting point. Your sister will help.”

“Thalia?”

The scene began to dissolve. “Good-bye, Jason. Beware Chicago. Your most dangerous mortal enemy waits there. If you are to die, it will be by her hand.”

“Who?” he demanded.

But Hera’s image faded, and Jason awoke.

His eyes snapped open. “Cyclops!”

“Whoa, sleepyhead.” Piper sat behind him on the bronze dragon, holding his waist to keep him balanced. Leo sat in front, driving. They flew peacefully through the winter sky as if nothing had happened.

“D-Detroit,” Jason stammered. “Didn’t we crash-land? I thought—”

“It’s okay,” Leo said. “We got away, but you got a nasty concussion. How you feeling?”

Jason’s head throbbed. He remembered the factory, then walking down the catwalk, then a creature looming over him—a face with one eye, a massive fist—and everything went black.

“How did you—the Cyclops—”

“Leo ripped them apart,” Piper said. “He was amazing. He can summon fire—”

“It was nothing,” Leo said quickly.

Piper laughed. “Shut up, Valdez. I’m going to tell him. Get over it.”

And she did—how Leo single-handedly defeated the Cyclopes family; how they freed Jason, then noticed the Cyclopes starting to re-form; how Leo had replaced the dragon’s wiring and gotten them back in the air just as they’d started to hear the Cyclopes roaring for vengeance inside the factory.

Jason was impressed. Taking out three Cyclopes with nothing but a tool kit? Not bad. It didn’t exactly scare him to hear how close he’d come to death, but it did make him feel horrible. He’d stepped right into an ambush and spent the whole fight knocked out while his friends fended for themselves. What kind of quest leader was he?

When Piper told him about the other kid the Cyclopes claimed to have eaten, the one in the purple shirt who spoke Latin, Jason felt like his head was going to explode. A son of Mercury … Jason felt like he should know that kid, but the name was missing from his mind.

“I’m not alone, then,” he said. “There are others like me.”

“Jason,” Piper said, “you were never alone. You’ve got us.”

“I—I know … but something Hera said. I was having a dream…”

He told them what he’d seen, and what the goddess had said inside her cage.

“An exchange?” Piper asked. “What does that mean?”

Jason shook his head. “But Hera’s gamble is me. Just by sending me to Camp Half-Blood, I have a feeling she broke some kind of rule, something that could blow up in a big way—”

“Or save us,” Piper said hopefully. “That bit about the sleeping enemy—that sounds like the lady Leo told us about.”

Leo cleared his throat. “About that … she kind of appeared to me back in Detroit, in a pool of Porta-Potty sludge.”

Jason wasn’t sure he’d heard that right. “Did you say … Porta-Potty?”

Leo told them about the big face in the factory yard. “I don’t know if she’s completely unkillable,” he said, “but she cannot be defeated by toilet seats. I can vouch for that. She wanted me to betray you guys, and I was like, ‘Pfft, right, I’m gonna listen to a face in the potty sludge.’”

“She’s trying to divide us.” Piper slipped her arms from around Jason’s waist. He could sense her tension without even looking at her.

“What’s wrong?” he asked.

“I just … Why are they toying with us? Who is this lady, and how is she connected to Enceladus?”

“Enceladus?” Jason didn’t think he’d heard that name before.

“I mean …” Piper’s voice quavered. “That’s one of the giants. Just one of the names I could remember.”

Jason got the feeling there was a lot more bothering her, but he decided he not to press her. She’d had a rough morning.

Leo scratched his head. “Well, I dunno about Enchiladas—”

“Enceladus,” Piper corrected.

“Whatever. But Old Potty Face mentioned another name. Porpoise Fear, or something?”

“Porphyrion?” Piper asked. “He was the giant king, I think.”

Jason envisioned that dark spire in the old reflecting pool—growing larger as Hera got weaker. “I’m going to take wild guess,” he said. “In the old stories, Porphyrion kidnapped Hera. That was the first shot in the war between the giants and the gods.”

“I think so,” Piper agreed. “But those myths are really garbled and conflicted. It’s almost like nobody wanted that story to survive. I just remember there was a war, and the giants were almost impossible to kill.”

“Heroes and gods had to work together,” Jason said. “That’s what Hera told me.”

“Kind of hard to do,” Leo grumbled, “if the gods won’t even talk to us.”

They flew west, and Jason became lost in his thoughts—all of them bad. He wasn’t sure how much time passed before the dragon dove through a break in the clouds, and below them, glittering in the winter sun, was a city at the edge of a massive lake. A crescent of skyscrapers lined the shore. Behind them, stretching out to the western horizon, was a vast grid of snow-covered neighborhoods and roads.

“Chicago,” Jason said.

He thought about what Hera had said in his dream. His worst mortal enemy would be waiting here. If he was going to die, it would be by her hand.

“One problem down,” Leo said. “We got here alive. Now, how do we find the storm spirits?”

Jason saw a flash of movement below them. At first he thought it was a small plane, but it was too small, too dark and fast. The thing spiraled toward the skyscrapers, weaving and changing shape—and, just for a moment it became the smoky figure of a horse.

“How about we follow that one,” Jason suggested, “and see where it goes?”

JASON WAS AFRAID THEY’D LOSE THEIR TARGET. The ventus moved like … well, like the wind.

“Speed up!” he urged.

“Bro,” Leo said, “if I get any closer, he’ll spot us. Bronze dragon ain’t exactly a stealth plane.”

“Slow down!” Piper yelped.

The storm spirit dove into the grid of downtown streets. Festus tried to follow, but his wingspan was way too wide. His left wing clipped the edge of a building, slicing off a stone gargoyle before Leo pulled up.

“Get above the buildings,” Jason suggested. “We’ll track him from there.”