“Wait, Thalia. About what happened back on the pier . . . I mean, with the manticore and the sacrifice—”

“I don’t want to talk about it.”

“You wouldn’t actually have . . . you know?”

She hesitated. “I was just shocked. That’s all.”

“Zeus didn’t send that lighting bolt at the car. It was Kronos. He’s trying to manipulate you, make you angry at your dad.”

She took a deep breath. “Percy, I know you’re trying to make me feel better. Thanks. But come on. We need to go.”

She stepped into the fog, into the Mist, and I followed.

When the fog cleared, I was still on the side of the mountain, but the road was dirt. The grass was thicker. The sunset made a bloodred slash across the sea. The summit of the mountain seemed closer now, swirling with storm clouds and raw power. There was only one path to the top, directly in front of us. And it led through a lush meadow of shadows and flowers: the garden of twilight, just like I’d seen in my dream.

If it hadn’t been for the enormous dragon, the garden would’ve been the most beautiful place I’d ever seen. The grass shimmered with silvery evening light, and the flowers were such brilliant colors they almost glowed in the dark. Stepping stones of polished black marble led around either side of a five-story-tall apple tree, every bough glittering with golden apples, and I don’t mean yellow golden apples like in the grocery store. I mean real golden apples. I can’t describe why they were so appealing, but as soon as I smelled their fragrance, I knew that one bite would be the most delicious thing I’d ever tasted.

“The apples of immortality,” Thalia said. “Hera’s wedding gift from Zeus.”

I wanted to step right up and pluck one, except for the dragon coiled around the tree.

Now, I don’t know what you think of when I say dragon. Whatever it is, it’s not scary enough. The serpent’s body was as thick as a booster rocket, glinting with coppery scales. He had more heads than I could count, as if a hundred deadly pythons had been fused together. He appeared to be asleep. The heads lay curled in a big spaghetti-like mound on the grass, all the eyes closed.

Then the shadows in front of us began to move. There was a beautiful, eerie singing, like voices from the bottom of a well. I reached for Riptide, but Zoë stopped my hand.

Four figures shimmered into existence, four young women who looked very much like Zoë. They all wore white Greek chitons. Their skin was like caramel. Silky black hair tumbled loose around their shoulders. It was strange, but I’d never realized how beautiful Zoë was until I saw her siblings, the Hesperides. They looked just like Zoë—gorgeous, and probably very dangerous.

“Sisters,” Zoë said.

“We do not see any sister,” one of the girls said coldly. “We see two half-bloods and a Hunter. All of whom shall soon die.”

“You’ve got it wrong.” I stepped forward. “Nobody is going to die.”

The girls studied me. They had eyes like volcanic rock, glassy and completely black.

“Perseus Jackson,” one of them said.

“Yes,” mused another. “I do not see why he is a threat.”

“Who said I was a threat?”

The first Hesperid glanced behind her, toward the top of the mountain. “They fear thee. They are unhappy that this one has not yet killed thee.”

She pointed at Thalia.

“Tempting sometimes,” Thalia admitted. “But no, thanks. He’s my friend.”

“There are no friends here, daughter of Zeus,” the girl said. “Only enemies. Go back.”

“Not without Annabeth,” Thalia said.

“And Artemis,” Zoë said. “We must approach the mountain.”

“You know he will kill thee,” the girl said. “You are no match for him.”

“Artemis must be freed,” Zoë insisted. “Let us pass.”

The girl shook her head. “You have no rights here anymore. We have only to raise our voices and Ladon will wake.”

“He will not hurt me,” Zoë said.

“No? And what about thy so-called friends?”

Then Zoë did the last thing I expected. She shouted, “Ladon! Wake!”

The dragon stirred, glittering like a mountain of pennies. The Hesperides yelped and scattered. The lead girl said to Zoë, “Are you mad?”

“You never had any courage, sister,” Zoë said. “That is thy problem.”

The dragon Ladon was writhing now, a hundred heads whipping around, tongues flickering and tasting the air. Zoë took a step forward, her arms raised.

“Zoë, don’t,” Thalia said. “You’re not a Hesperid anymore. He’ll kill you.”

“Ladon is trained to protect the tree,” Zoë said. “Skirt around the edges of the garden. Go up the mountain. As long as I am a bigger threat, he should ignore thee.”

“Should,” I said. “Not exactly reassuring.”

“It is the only way,” she said. “Even the three of us together cannot fight him.”

Ladon opened his mouths. The sound of a hundred heads hissing at once sent a shiver down my back, and that was before his breath hit me. The smell was like acid. It made my eyes burn, my skin crawl, and my hair stand on end. I remembered the time a rat had died inside our apartment wall in New York in the middle of the summer. This stench was like that, except a hundred times stronger, and mixed with the smell of chewed eucalyptus. I promised myself right then that I would never ask a school nurse for another cough drop.

I wanted to draw my sword. But then I remembered my dream of Zoë and Hercules, and how Hercules had failed in a head-on assault. I decided to trust Zoë’s judgment.

Thalia went left. I went right. Zoë walked straight toward the monster.

“It’s me, my little dragon,” Zoë said. “Zoë has come back.”

Ladon shifted forward, then back. Some of the mouths closed. Some kept hissing. Dragon confusion. Meanwhile, the Hesperides shimmered and turned into shadows. The voice of the eldest whispered, “Fool.”

“I used to feed thee by hand,” Zoë continued, speaking in a soothing voice as she stepped toward the golden tree. “Do you still like lamb’s meat?”

The dragon’s eyes glinted.

Thalia and I were about halfway around the garden. Ahead, I could see a single rocky trail leading up to the black peak of the mountain. The storm swirled above it, spinning on the summit like it was the axis for the whole world.

We’d almost made it out of the meadow when something went wrong. I felt the dragon’s mood shift. Maybe Zoë got too close. Maybe the dragon realized he was hungry. Whatever the reason, he lunged at Zoë.

Two thousand years of training kept her alive. She dodged one set of slashing fangs and tumbled under another, weaving through the dragon’s heads as she ran in our direction, gagging from the monster’s horrible breath.

I drew Riptide to help.

“No!” Zoë panted. “Run!”

The dragon snapped at her side, and Zoë cried out. Thalia uncovered Aegis, and the dragon hissed. In his moment of indecision, Zoë sprinted past us up the mountain, and we followed.

The dragon didn’t try to pursue. He hissed and stomped the ground, but I guess he was well trained to guard that tree. He wasn’t going to be lured off, even by the tasty prospect of eating some heroes.

We ran up the mountain as the Hesperides resumed their song in the shadows behind us. The music didn’t sound so beautiful to me now—more like the sound track for a funeral.

At the top of mountain were ruins, blocks of black granite and marble as big as houses. Broken columns. Statues of bronze that looked as though they’d been half melted.

“The ruins of Mount Othrys,” Thalia whispered in awe.

“Yes,” Zoë said. “It was not here before. This is bad.”

“What’s Mount Othrys?” I asked, feeling like a fool as usual.

“The mountain fortress of the Titans,” Zoë said. “In the first war, Olympus and Othrys were the two rival capitals of the world. Othrys was—” She winced and held her side.

“You’re hurt,” I said. “Let me see.”