“The giants,” she said. “You’re working for them?”

“They are our neighbors.” Hagno smiled. “Their chambers lie beyond this place, where the aqueduct’s water was diverted for the games. Once we have dealt with you…once you have helped us…the twins have promised we will never suffer again.”

Hagno turned to Jason. “You, child of Jupiter—for the horrible betrayal of your predecessor who brought us here, you shall pay. I know the sky god’s powers. I raised him as a baby! Once, we nymphs controlled the rain above our wells and springs. When I am done with you, we will have that power again. And Percy Jackson, child of the sea god…from you, we will take water, an endless supply of water.”

“Endless?” Percy’s eyes darted from one nymph to the other. “Uh…look, I don’t know about endless. But maybe I could spare a few gallons.”

“And you, Piper McLean.” Hagno’s purple eyes glistened. “So young, so lovely, so gifted with your sweet voice. From you, we will reclaim our beauty. We have saved our last life force for this day. We are very thirsty. From you three, we shall drink!”

All nine niches glowed. The nymphs disappeared, and water poured from their alcoves—sickly dark water, like oil.

Chapter 43

Piper needed a miracle, not a bedtime story. But right then, standing in shock as black water poured in around her legs, she recalled the legend Achelous had mentioned—the story of the flood.

Not the Noah story, but the Cherokee version that her father used to tell her, with the dancing ghosts and the skeleton dog.

When she was little, she would cuddle next to her dad in his big recliner. She’d gaze out the windows at the Malibu coastline, and her dad would tell her the story he’d heard from Grandpa Tom back on the rez in Oklahoma.

“This man had a dog,” her father always began.

“You can’t start a story that way!” Piper protested. “You have to say Once upon a time.”

Dad laughed. “But this is a Cherokee story. They are pretty straightforward. So, anyway, this man had a dog. Every day the man took his dog to the edge of the lake to get water, and the dog would bark furiously at the lake, like he was mad at it.”

“Was he?”

“Be patient, sweetheart. Finally the man got very annoyed with his dog for barking so much, and he scolded it. ‘Bad dog! Stop barking at the water. It’s only water!’ To his surprise, the dog looked right at him and began to talk.”

“Our dog can say Thank you,” Piper volunteered. “And she can bark Out.”

“Sort of,” her dad agreed. “But this dog spoke entire sentences. The dog said, ‘One day soon, the storms will come. The waters will rise, and everyone will drown. You can save yourself and your family by building a raft, but first you will need to sacrifice me. You must throw me into the water.’”

“That’s terrible!” Piper said. “I would never drown my dog!”

“The man probably said the same thing. He thought the dog was lying—I mean, once he got over the shock that his dog could talk. When he protested, the dog said, ‘If you don’t believe me, look at the scruff of my neck. I am already dead.’”

“That’s sad! Why are you telling me this?”

“Because you asked me to,” her dad reminded her. And indeed, something about the story fascinated Piper. She had heard it dozens of times, but she kept thinking about it.

“Anyway,” said her dad, “the man grabbed the dog by the scruff of its neck and saw that its skin and fur were already coming apart. Underneath was nothing but bones. The dog was a skeleton dog.”

“Gross.”

“I agree. So with tears in his eyes, the man said good-bye to his annoying skeleton dog and tossed it into the water, where it promptly sank. The man built a raft, and when the flood came, he and his family survived.”

“Without the dog.”

“Yes. Without the dog. When the rains subsided, and the raft landed, the man and his family were the only ones alive. The man heard sounds from the other side of a hill—like thousands of people laughing and dancing—but when he raced to the top, alas, down below he saw nothing except bones littering the ground—thousands of skeletons of all the people who had died in the flood. He realized the ghosts of the dead had been dancing. That was the sound he heard.”

Piper waited. “And?”

“And, nothing. The end.”

“You can’t end it that way! Why were the ghosts dancing?”

“I don’t know,” Dad said. “Your grandfather never felt the need to explain. Maybe the ghosts were happy that one family had survived. Maybe they were enjoying the afterlife. They’re ghosts. Who can say?”

Piper was very unsatisfied with that. She had so many unanswered questions. Did the family ever find another dog? Obviously not all dogs drowned, because she herself had a dog.

She couldn’t shake the story. She never looked at dogs the same way, wondering if one of them might be a skeleton dog. And she didn’t understand why the family had to sacrifice their dog to survive. Sacrificing yourself to save your family seemed like a noble thing—a very doglike thing to do.

Now, in the nymphaeum in Rome, as the dark water rose to her waist, Piper wondered why the river god Achelous had mentioned that story.

She wished she had a raft, but she feared she was more like the skeleton dog. She was already dead.

Chapter 44

The basin filled with alarming speed. Piper, Jason, and Percy pounded on the walls, looking for an exit, but they found nothing. They climbed into the alcoves to gain some height, but with water pouring out of each niche, it was like trying to balance at the edge of a waterfall. Even as Piper stood in a niche, the water was soon up to her knees. From the floor, it was probably eight feet deep and rising fast.

“I could try lightning,” Jason said. “Maybe blast a hole in the roof?”

“That could bring down the whole room and crush us,” Piper said.

“Or electrocute us,” Percy added.

“Not many choices,” Jason said.

“Let me search the bottom,” Percy said. “If this place was built as a fountain, there has to be a way to drain the thing. You guys, check the niches for secret exits. Maybe the seashells are knobs, or something.” It was a desperate idea, but Piper was glad for something to do.

Percy jumped in the water. Jason and Piper climbed from niche to niche, kicking and pounding, wiggling seashells embedded in the stone; but they had no luck.

Sooner than Piper expected, Percy broke the surface, gasping and flailing. She offered her hand, and he almost pulled her in before she could help him up.

“Couldn’t breathe,” he choked. “The water…not normal. Hardly made it back.”

The life force of the nymphs, Piper thought. It was so poisoned and malicious, even a son of the sea god couldn’t control it.

As the water rose around her, Piper felt it affecting her too. Her leg muscles trembled like she’d been running for miles. Her hands turned wrinkled and dry, despite being in the middle of a fountain.

The boys moved sluggishly. Jason’s face was pale. He seemed to be having trouble holding his sword. Percy was drenched and shivering. His hair didn’t look quite so dark, as if the color was leaching out.

“They’re taking our power,” Piper said. “Draining us.”

“Jason,” Percy coughed, “do the lightning.”

Jason raised his sword. The room rumbled, but no lightning appeared. The roof didn’t break. Instead, a miniature rainstorm formed at the top of the chamber. Rain poured down, filling the fountain even faster, but it wasn’t normal rain. The stuff was just as dark as the water in the pool. Every drop stung Piper’s skin.

“Not what I wanted,” Jason said.

The water was up to their necks now. Piper could feel her strength fading. Grandpa Tom’s story about the water cannibals was true. Bad nymphs would steal her life.

“We’ll survive,” she murmured to herself, but she couldn’t charmspeak her way out of this. Soon the poisonous water would be over their heads. They’d have to swim, and this stuff was already paralyzing them.

They would drown, just like in the visions she’d seen.

Percy started pushing the water away with the back of his hand, like he was shooing a bad dog. “Can’t—can’t control it!”

You will need to sacrifice me, the skeleton dog had said in the story. You must throw me into the water.

Piper felt like someone had grabbed the scruff of her neck and exposed the bones. She clutched her cornucopia.

“We can’t fight this,” she said. “If we hold back, that just makes us weaker.”

“What do you mean?” Jason shouted over the rain.

The water was up to their chins. Another few inches, and they’d have to swim. But the water wasn’t halfway to the ceiling yet. Piper hoped that meant that they still had time.

“The horn of plenty,” she said. “We have to overwhelm the nymphs with fresh water, give them more than they can use. If we can dilute this poisonous stuff—”

“Can your horn do that?” Percy struggled to keep his head above water, which was obviously a new experience for him. He looked scared out of his mind.

“Only with your help.” Piper was beginning to understand how the horn worked. The good stuff it produced didn’t come from nowhere. She’d only been able to bury Hercules in groceries when she had concentrated on all her positive experiences with Jason.

To create enough clean fresh water to fill this room, she needed to go even deeper, tap her emotions even more. Unfortunately, she was losing her ability to focus.

“I need you both to channel everything you’ve got into the cornucopia,” she said. “Percy, think about the sea.”

“Salt water?”

“Doesn’t matter! As long as it’s clean. Jason, think about rainstorms—much more rain. Both of you hold the cornucopia.”

They huddled together as the water lifted them off their ledges. Piper tried to remember the safety lessons her dad had given her when they had started surfing. To help someone who’s drowning, you put your arm around them from behind and kick your legs in front of you, moving backward like you’re doing the backstroke. She wasn’t sure if the same strategy could work with two other people, but she put one arm around each boy and tried to keep them afloat as they held the cornucopia between them.

Nothing happened. The rain came down in sheets, still dark and acidic.

Piper’s legs felt like lead. The rising water swirled, threatening to pull her under. She could feel her strength fading.

“No good!” Jason yelled, spitting water.

“We’re getting nowhere,” Percy agreed.

“You have to work together,” Piper cried, hoping she was right. “Both of you think of clean water—a storm of water. Don’t hold anything back. Picture all your power, all your strength leaving you.”

“That’s not hard!” Percy said.