Jason woke up quickly. He crawled forward, grabbing their seats for balance. “We’ve got to be getting close.”

Leo was too busy wrestling with the stick to reply. Suddenly it wasn’t so easy to drive the chopper. Its movements turned sluggish and jerky. The whole machine shuddered in the icy wind. The helicopter probably hadn’t been prepped for cold-weather flying. The controls refused to respond, and they started to lose altitude.

Below them, the ground was a dark quilt of trees and fog. The ridge of a hill loomed in front of them and Leo yanked the stick, just clearing the treetops.

“There!” Jason shouted.

A small valley opened up before them, with the murky shape of a building in the middle. Leo aimed the helicopter straight for it. All around them were flashes of light that reminded Leo of the tracer fire at Midas’s compound. Trees cracked and exploded at the edges of the clearing. Shapes moved through the mist. Combat seemed to be everywhere.

He set down the helicopter in an icy field about fifty yards from the house and killed the engine. He was about to relax when he heard a whistling sound and saw a dark shape hurtling toward them out of the mist.

“Out!” Leo screamed.

They leaped from the helicopter and barely cleared the rotors before a massive BOOM shook the ground, knocking Leo off his feet and splattering ice all over him.

He got up shakily and saw that the world’s largest snowball—a chunk of snow, ice, and dirt the size of a garage—had completely flattened the Bell 412.

“You all right?” Jason ran up to him, Piper at his side. They both looked fine except for being speckled with snow and mud.

“Yeah.” Leo shivered. “Guess we owe that ranger lady a new helicopter.”

Piper pointed south. “Fighting’s over there.” Then she frowned. “No … it’s all around us.”

She was right. The sounds of combat rang across the valley. The snow and mist made it hard to tell for sure, but there seemed to be a circle of fighting all around the Wolf House.

Behind them loomed Jack London’s dream home—a massive ruin of red and gray stones and rough-hewn timber beams. Leo could imagine how it had looked before it burned down—a combination log cabin and castle, like a billionaire lumberjack might build. But in the mist and sleet, the place had a lonely, haunted feel. Leo could totally believe the ruins were cursed.

“Jason!” a girl’s voice called.

Thalia appeared from the fog, her parka caked with snow. Her bow was in her hand, and her quiver was almost empty. She ran toward them, but made it only a few steps before a six-armed ogre—one of the Earthborn—burst out of the storm behind her, a raised club in each hand.

“Look out!” Leo yelled. They rushed to help, but Thalia had it under control. She launched herself into a flip, notching an arrow as she pivoted like a gymnast and landed in a kneeling position. The ogre got a silver arrow right between the eyes and melted into a pile of clay.

Thalia stood and retrieved her arrow, but the point had snapped off. “That was my last one.” She kicked the pile of clay resentfully. “Stupid ogre.”

“Nice shot, though,” Leo said.

Thalia ignored him as usual (which no doubt meant she thought he was as cool as ever). She hugged Jason and nodded to Piper. “Just in time. My Hunters are holding a perimeter around the mansion, but we’ll be overrun any minute.”

“By Earthborn?” Jason asked.

“And wolves—Lycaon’s minions.” Thalia blew a fleck of ice off her nose. “Also storm spirits—”

“But we gave them to Aeolus!” Piper protested.

“Who tried to kill us,” Leo reminded her. “Maybe he’s helping Gaea again.”

“I don’t know,” Thalia said. “But the monsters keep re-forming almost as fast as we can kill them. We took the Wolf House with no problem: surprised the guards and sent them straight to Tartarus. But then this freak snowstorm blew in. Wave after wave of monsters started attacking. Now we’re surrounded. I don’t know who or what is leading the assault, but I think they planned this. It was a trap to kill anyone who tried to rescue Hera.”

“Where is she?” Jason asked.

“Inside,” Thalia said. “We tried to free her, but we can’t figure out how to break the cage. It’s only a few minutes until the sun goes down. Hera thinks that’s the moment when Porphyrion will be reborn. Plus, most monsters are stronger at night. If we don’t free Hera soon—”

She didn’t need to finish the thought.

Leo, Jason, and Piper followed her into the ruined mansion.

Jason stepped over the threshold and immediately collapsed.

“Hey!” Leo caught him. “None of that, man. What’s wrong?”

“This place …” Jason shook his head. “Sorry … It came rushing back to me.”

“So you have been here,” Piper said.

“We both have,” Thalia said. Her expression was grim, like she was reliving someone’s death. “This is where my mom took us when Jason was a child. She left him here, told me he was dead. He just disappeared.”

“She gave me to the wolves,” Jason murmured. “At Hera’s insistence. She gave me to Lupa.”

“That part I didn’t know.” Thalia frowned. “Who is Lupa?”

An explosion shook the building. Just outside, a blue mushroom cloud billowed up, raining snowflakes and ice like a nuclear blast made of cold instead of heat.

“Maybe this isn’t the time for questions,” Leo suggested. “Show us the goddess.”

Once inside, Jason seemed to get his bearings. The house was built in a giant U, and Jason led them between the two wings to an outside courtyard with an empty reflecting pool. At the bottom of the pool, just as Jason had described from his dream, two spires of rock and root tendrils had cracked through the foundation.

One of the spires was much bigger—a solid dark mass about twenty feet high, and to Leo it looked like a stone body bag. Underneath the mass of fused tendrils he could make out the shape of a head, wide shoulders, a massive chest and arms, like the creature was stuck waist deep in the earth. No, not stuck—rising.

On the opposite end of the pool, the other spire was smaller and more loosely woven. Each tendril was as thick as a telephone pole, with so little space between them that Leo doubted he could’ve gotten his arm through. Still, he could see inside. And in the center of the cage stood Tía Callida.

She looked exactly like Leo remembered: dark hair covered with a shawl, the black dress of a widow, a wrinkled face with glinting, scary eyes.

She didn’t glow or radiate any sort of power. She looked like a regular mortal woman, his good old psychotic babysitter.

Leo dropped into the pool and approached the cage. “Hola, Tía. Little bit of trouble?”

She crossed her arms and sighed in exasperation. “Don’t inspect me like I’m one of your machines, Leo Valdez. Get me out of here!”

Thalia stepped next to him and looked at the cage with distaste—or maybe she was looking at the goddess. “We tried everything we could think of, Leo, but maybe my heart wasn’t in it. If it was up to me, I’d just leave her in there.”

“Ohh, Thalia Grace,” the goddess said. “When I get out of here, you’ll be sorry you were ever born.”

“Save it!” Thalia snapped. “You’ve been nothing but a curse to every child of Zeus for ages. You sent a bunch of intestinally challenged cows after my friend Annabeth—”

“She was disrespectful!”

“You dropped a statue on my legs.”

“It was an accident!”

“And you took my brother!” Thalia’s voice cracked with emotion. “Here—on this spot. You ruined our lives. We should leave you to Gaea!”

“Hey,” Jason intervened. “Thalia—Sis—I know. But this isn’t the time. You should help your Hunters.”

Thalia clenched her jaw. “Fine. For you, Jason. But if you ask me, she isn’t worth it.”

Thalia turned, leaped out of the pool, and stormed from the building.

Leo turned to Hera with grudging respect. “Intestinally challenged cows?”

“Focus on the cage, Leo,” she grumbled. “And Jason—you are wiser than your sister. I chose my champion well.”

“I’m not your champion, lady,” Jason said. “I’m only helping you because you stole my memories and you’re better than the alternative. Speaking of which, what’s going on with that?”

He nodded to the other spire that looked like the king-size granite body bag. Was Leo imagining it, or had it grown taller since they’d gotten here?

“That, Jason,” Hera said, “is the king of the giants being reborn.”

“Gross,” Piper said.

“Indeed,” Hera said. “Porphyrion, the strongest of his kind. Gaea needed a great deal of power to raise him again —my power. For weeks I’ve grown weaker as my essence was used to grow him a new form.”

“So you’re like a heat lamp,” Leo guessed. “Or fertilizer.”

The goddess glared at him, but Leo didn’t care. This old lady had been making his life miserable since he was a baby. He totally had rights to rag on her.

“Joke all you wish,” Hera said in a clipped tone. “But at sundown, it will be too late. The giant will awake. He will offer me a choice: marry him, or be consumed by the earth. And I cannot marry him. We will all be destroyed. And as we die, Gaea will awaken.”

Leo frowned at the giant’s spire. “Can’t we blow it up or something?”

“Without me, you do not have the power,” Hera said. “You might as well try to destroy a mountain.”

“Done that once today,” Jason said.

“Just hurry up and let me out!” Hera demanded.

Jason scratched his head. “Leo, can you do it?”

“I don’t know.” Leo tried not to panic. “Besides, if she’s a goddess, why hasn’t she busted herself out?”

Hera paced furiously around her cage, cursing in Ancient Greek. “Use your brain, Leo Valdez. I picked you because you’re intelligent. Once trapped, a god’s power is useless. Your own father trapped me once in a golden chair. It was humiliating! I had to beg—beg him for my freedom and apologize for throwing him off Olympus.”

“Sounds fair,” Leo said.

Hera gave him the godly stink-eye. “I’ve watched you since you were a child, son of Hephaestus, because I knew you could aid me at this moment. If anyone can find a way to destroy this abomination, it is you.”

“But it’s not a machine. It’s like Gaea thrust her hand out of the ground and …” Leo felt dizzy. The line of their prophecy came back to him: The forge and dove shall break the cage.“Hold on. I do have an idea. Piper, I’m going to need your help. And we’re going to need time.”

The air turned brittle with cold. The temperature dropped so fast, Leo’s lips cracked and his breath changed to mist. Frost coated the walls of the Wolf House. Venti rushed in —but instead of winged men, these were shaped like horses, with dark storm-cloud bodies and manes that crackled with lightning. Some had silver arrows sticking out of their flanks. Behind them came red-eyed wolves and the six-armed Earthborn.