“But force it out!” she said. “Offer up everything, like—like you’re already dead, and your only goal is to help the nymphs. It’s got to be a gift…a sacrifice.”

They got quiet at that word.

“Let’s try again,” Jason said. “Together.”

This time Piper bent all her concentration toward the horn of plenty as well. The nymphs wanted her youth, her life, her voice? Fine. She gave it up willingly and imagined all of her power flooding out of her.

I’m already dead, she told herself, as calm as the skeleton dog. This is the only way.

Clear water blasted from the horn with such force, it pushed them against the wall. The rain changed to a white torrent, so clean and cold, it made Piper gasp.

“It’s working!” Jason cried.

“Too well,” Percy said. “We’re filling the room even faster!”

He was right. The water rose so quickly, the roof was now only a few feet away. Piper could’ve reached up and touched the miniature rain clouds.

“Don’t stop!” she said. “We have to dilute the poison until the nymphs are cleansed.”

“What if they can’t be cleansed?” Jason asked. “They’ve been down here turning evil for thousands of years.”

“Just don’t hold back,” Piper said. “Give everything. Even if we go under—”

Her head hit the ceiling. The rainclouds dissipated and melted into the water. The horn of plenty kept blasting out a clean torrent.

Piper pulled Jason closer and kissed him.

“I love you,” she said.

The words just poured out of her, like the water from the cornucopia. She couldn’t tell what his reaction was, because then they were underwater.

She held her breath. The current roared in her ears. Bubbles swirled around her. Light still rippled through the room, and Piper was surprised she could see it. Was the water getting clearer?

Her lungs were about to burst, but Piper poured her last energy into the cornucopia. Water continued to stream out, though there was no room for more. Would the walls crack under the pressure?

Piper’s vision went dark.

She thought the roar in her ears was her own dying heartbeat. Then she realized the room was shaking. The water swirled faster. Piper felt herself sinking.

With her last strength, she kicked upward. Her head broke the surface and she gasped for breath. The cornucopia stopped. The water was draining almost as fast as it had filled the room.

With a cry of alarm, Piper realized that Percy’s and Jason’s faces were still underwater. She hoisted them up. Instantly, Percy gulped and began to thrash, but Jason was as lifeless as a rag doll.

Piper clung to him. She yelled his name, shook him, and slapped his face. She barely noticed when all the water had drained away and left them on the damp floor.

“Jason!” She tried desperately to think. Should she turn him on his side? Slap his back?

“Piper,” Percy said, “I can help.”

He knelt next to her and touched Jason’s forehead. Water gushed from Jason’s mouth. His eyes flew open, and a clap of thunder threw Percy and Piper backward.

When Piper’s vision cleared, she saw Jason sitting up, still gasping, but the color was coming back to his face.

“Sorry,” he coughed. “Didn’t mean to—”

Piper tackled him with a hug. She would have kissed him, but she didn’t want to suffocate him.

Percy grinned. “In case you’re wondering, that was clean water in your lungs. I could make it come out with no problem.”

“Thanks, man.” Jason clasped his hand weakly. “But I think Piper’s the real hero. She saved us all.”

Yes, she did, a voice echoed through the chamber.

The niches glowed. Nine figures appeared, but they were no longer withered creatures. They were young, beautiful nymphs in shimmering blue gowns, their glossy black curls pinned up with silver and gold brooches. Their eyes were gentle shades of blue and green.

As Piper watched, eight of the nymphs dissolved into vapor and floated upward. Only the nymph in the center remained.

“Hagno?” Piper asked.

The nymph smiled. “Yes, my dear. I didn’t think such selflessness existed in mortals…especially in demigods. No offense.”

Percy got to his feet. “How could we take offense? You just tried to drown us and suck out our lives.”

Hagno winced. “Sorry about that. I was not myself. But you have reminded me of the sun and the rain and the streams in the meadows. Percy and Jason, thanks to you, I remembered the sea and the sky. I am cleansed. But mostly, thanks to Piper. She shared something even better than clear running water.” Hagno turned to her. “You have a good nature, Piper. And I’m a nature spirit. I know what I’m talking about.”

Hagno pointed to the other side of the room. The stairs to the surface reappeared. Directly underneath, a circular opening shimmered into existence, like a sewer pipe, just big enough to crawl through. Piper suspected this was how the water had drained out.

“You may return to the surface,” Hagno said. “Or, if you insist, you may follow the waterway to the giants. But choose quickly, because both doors will fade soon after I am gone. That pipe connects to the old aqueduct line, which feeds both this nymphaeum and the hypogeum that the giants call home.”

“Ugh.” Percy pressed on his temples. “Please, no more complicated words.”

“Oh, home is not a complicated word.” Hagno sounded completely sincere. “I thought it was, but now you have unbound us from this place. My sisters have gone to seek new homes…a mountain stream, perhaps, or a lake in a meadow. I will follow them. I cannot wait to see the forests and grasslands again, and the clear running water.”

“Uh,” Percy said nervously, “things have changed up above in the last few thousand years.”

“Nonsense,” Hagno said. “How bad could it be? Pan would not allow nature to become tainted. I can’t wait to see him, in fact.”

Percy looked like he wanted to say something, but he stopped himself.

“Good luck, Hagno,” Piper said. “And thank you.”

The nymph smiled one last time and vaporized.

Briefly, the nymphaeum glowed with a softer light, like a full moon. Piper smelled exotic spices and blooming roses. She heard distant music and happy voices talking and laughing. She guessed she was hearing hundreds of years of parties and celebrations that had been held at this shrine in ancient times, as if the memories had been freed along with the spirits.

“What is that?” Jason asked nervously.

Piper slipped her hand into his. “The ghosts are dancing. Come on. We’d better go meet the giants.”

Chapter 45

Percy was tired of water.

If he said that aloud, he would probably get kicked out of Poseidon’s Junior Sea Scouts, but he didn’t care.

After barely surviving the nymphaeum, he wanted to go back to the surface. He wanted to be dry and sit in the warm sunshine for a long time—preferably with Annabeth.

Unfortunately, he didn’t know where Annabeth was. Frank, Hazel, and Leo were missing in action. He still had to save Nico di Angelo, assuming the guy wasn’t already dead. And there was that little matter of the giants destroying Rome, waking Gaea, and taking over the world.

Seriously, these monsters and gods were thousands of years old. Couldn’t they take a few decades off and let Percy live his life? Apparently not.

Percy took the lead as they crawled down the drainage pipe. After thirty feet, it opened into a wider tunnel. To their left, somewhere in the distance, Percy heard rumbling and creaking, like a huge machine needed oiling. He had absolutely no desire to find out what was making that sound, so he figured that must be the way to go.

Several hundred feet later, they reached a turn in the tunnel. Percy held up his hand, signaling Jason and Piper to wait. He peeked around the corner.

The corridor opened into a vast room with twenty-foot ceilings and rows of support columns. It looked like the same parking-garage-type area Percy had seen in his dreams, but now much more crowded with stuff.

The creaking and rumbling came from huge gears and pulley systems that raised and lowered sections of the floor for no apparent reason. Water flowed through open trenches (oh, great, more water), powering waterwheels that turned some of the machines. Other machines were connected to huge hamster wheels with hellhounds inside. Percy couldn’t help thinking of Mrs. O’Leary, and how much she would hate being trapped inside one of those.

Suspended from the ceiling were cages of live animals—a lion, several zebras, a whole pack of hyenas, and even an eight-headed hydra. Ancient-looking bronze and leather conveyor belts trundled along with stacks of weapons and armor, sort of like the Amazons’ warehouse in Seattle, except this place was obviously much older and not as well organized.

Leo would love it, Percy thought. The whole room was like one massive, scary, unreliable machine.

“What is it?” Piper whispered.

Percy wasn’t even sure how to answer. He didn’t see the giants, so he gestured for his friends to come forward and take a look.

About twenty feet inside the doorway, a life-size wooden cutout of a gladiator popped up from the floor. It clicked and whirred along a conveyor belt, got hooked on a rope, and ascended through a slot in the roof.

Jason murmured, “What the heck?”

They stepped inside. Percy scanned the room. There were several thousand things to look at, most of them in motion, but one good aspect of being an ADHD demigod was that Percy was comfortable with chaos. About a hundred yards away, he spotted a raised dais with two empty oversized praetor chairs. Standing between them was a bronze jar big enough to hold a person.

“Look.” He pointed it out to his friends.

Piper frowned. “That’s too easy.”

“Of course,” Percy said.

“But we have no choice,” Jason said. “We’ve got to save Nico.”

“Yeah.” Percy started across the room, picking his way around conveyor belts and moving platforms.

The hellhounds in the hamster wheels paid them no attention. They were too busy running and panting, their red eyes glowing like headlights. The animals in the other cages gave them bored looks, as if to say, I’d kill you, but it would take too much energy.

Percy tried to watch out for traps, but everything here looked like a trap. He remembered how many times he’d almost died in the labyrinth a few years ago. He really wished Hazel were here so she could help with her underground skills (and of course so she could be reunited with her brother).

They jumped over a water trench and ducked under a row of caged wolves. They had made it about halfway to the bronze jar when the ceiling opened over them. A platform lowered. Standing on it like an actor, with one hand raised and his head high, was the purple-haired giant Ephialtes.

Just like Percy had seen in his dreams, the Big F was small by giant standards—about twelve feet tall—but he had tried to make up for it with his loud outfit. He’d changed out of the gladiator armor and was now wearing a Hawaiian shirt that even Dionysus would’ve found vulgar. It had a garish print made up of dying heroes, horrible tortures, and lions eating slaves in the Colosseum. The giant’s hair was braided with gold and silver coins. He had a ten-foot spear strapped to his back, which wasn’t a good fashion statement with the shirt. He wore bright white jeans and leather sandals on his…well, not feet, but curved snakeheads. The snakes flicked their tongues and writhed as if they didn’t appreciate holding up the weight of a giant.