Disclaimer: Everything belongs to Rick Riordan

Chapter 1:

Piper's POV

Finding the place was easy. Percy lead us right to it, on an abandoned stretch of hillside overlooking the ruined Forum.

Getting in was easy too. Jason's gold sword cut through the padlock, and the metal gate creaked open. No mortals saw us.

"I'll go first," Jason said.

"No!" I yelped.

Both boys turned toward me.

"Pipes, what is it?" Jason asked. "That image in the blade . . . you've seen it before, haven't you?"

I nodded, my eyes stinging. "I didn't know how to tell you. I saw the room down there filling with water. I saw the three of us drowning."

Not only am I scared of losing Jason and Percy, I don't want anyone to find out about my secret.

Jason and Percy frowned. Jason gave me a look of sympathy. He thinks i'm scared of water. If only I could tell him the truth.

"I can't drown," Percy said, though he sounded like he was asking a question.

"Maybe the future has changed," Jason speculated. "In the image you shoued us just now, there wasn't any water."

I wished he was right, but i suspected they wouldn't be so lucky.

Especially me. I thought to myself.

"Look," Percy said. "I'll check it out first. It's fine. Be right back."

Before I could object, he disappeared down the stairwell.

I counted silently as we waited for him to come around thirty-five, I heard his footsteps, and he appeared at the top, looking more baffled than relieved.

"Good news: no water," he said. "Bad news: I don't see any exit exits down there. And, uh, weird news: well, you should see this."

We cautiously descended. Percy took the lead, with Riptide drawn. I followed, and Jason walked behind me, guarding our backs. The stairwell was a cramped corkscrew of masonry, no more than six feet in diameter. Even though Percy had given the "all clear," I kept my eyes open for traps. . . and water. With every turn of the stairs, I anticipated an ambush. I had no weapon, just the cornucopia on a leather cord over my shoulder. If worse came to worst, the boys' swords wouldn't do much good in such closed quarters. Maybe I could shoot our enemies with high-velocity smoked hams.

As we wound our way underground, I saw old graffiti gouged into the stones: Roman numerals, names, and phrases in Italian. That meant other people had been down here more recently than the Roman Empire, but I wasn't reassured. Especially after remembering the water in the image. If monsters were below, they'd ignore mortals, waiting for some nice juicy demigods to come along.

Finally, we reached the bottom.

Percy turned. "Watch your step."

Well you don't have to tell me twice. I thought to myself.

He jumped to the floor of the cylindrical room, which was five feet lower than the stairwell. Why would someone design a set of stairs like that? I had no idea. Maybe the room and the stairwell had been built during different time periods.

I wanted to turn and exit, but I couldn't do that with Jason behind me, and I couldn't just leave Percy down here. I clambered down, and Jason followed.

The room was just like I'd seen it in Katoptris's blade, except there was no water. The curved walls had once been painted with frescoes, which were now faded to eggshell white with only flecks of color. The domed ceiling was about fifty feet above.

Around the back side of the room, opposite the stairwell, nine alcoves were carved into the wall. Each niche was about five feet off the floor and big enough for a human-sized statue, but each was empty.

The air felt cold and dry. A Percy had said, there were no other exits.

"All right." Percy raised his eyebrows. "Here's the weird part. Watch."

He stepped to the middle of the room.

Instantly, green and blue lights rippled across the walls. I heard the sound of a fountain, which made me jump unnoticeably, but there was no water. There didn't seem to be any source of light except for Percy and Jason's blades.

"Do you smell the ocean?" Percy asked.

I hadn't noticed at first. I was standing next to Percy, and he always smelled like the sea. But he was right. The scent of salt water and storm was getting stronger, like a summer hurricane approaching. This made me very nervous, I'm not ready to reveal my secret yet! I'm guessing that Jason sensed my distress because he grabbed my hand, gave it a squeeze, and let go.

"An illusion?" I asked, hoping it was and illusion. All of a sudden, I felt strangely thirsty. I can't get thirsty, I'm a mermaid! My stress levels were probably off the chart.

"I don't know," Percy said. "I feel like there should be water here-lot of water. But there isn't any. I've never been in a place like this."

Nice going Percy, way to make me feel better.

Jason moved to the front row of niches. He touched the bottom shelf of the nearest one, which was just at his eye level. "This stone . . . it's embedded with seashells. This is a nymphaeum."

My mouth was definitely getting dryer. "A what?"

"We have one at Camp Jupiter," Jason said, "on Temple Hill. It's a shrine to the nymphs."

I ran my hand along the bottom of another niche. Jason was right. The alcove was studded with cowries, conches, and scallops. The seashells seemed to dance in the watery light. They were ice-cold to the touch. Oh how I miss the ocean, where I can be all alone and swim with the fish and dolphins.

I had always thought of nymphs as friendly spirits-silly and flirtatious, generally harmless. They got along well with the children of Aphrodite. They loved to share gossip and beauty tips. This place, though, didn't feel like the canoe lake back at Camp Half-Blood, or the streams in the woods where I normally met nymphs. This place felt unnatural, hostile, and very dry.

Jason stepped back and examined the row of alcoves. "Shrines like this were all over the place in Ancient Rome. Rich people had them outside their villas to honor nymphs, to make sure the local water was always fresh. Some shrines were built around natural springs, but most were man-made."

"So. . . no natural nymphs lived here?" I asked hopefully.

"Not sure," Jason said. "This place where we're standing would have been a pool with a fountain. A lot of times, if the nymphaeum belonged to a demigod, he or she would invite nymphs to live there. If the spirits took up residence, that was considered good luck."

This is making me really nervous.

"For the owner," Percy guessed. "But it would also bind the nymphs to a new water source, which would be great if the fountain was in a nice sunny park with fresh water pumped in through the aqueducts-"

"But this place has been underground for centuries," I guessed. "Dry and buried. What would happen to the nymphs?" I hope this place stays dry and buried.

The sound of water changed to a chorus of hissing, like ghostly snakes. The rippling light shifted from sea blue and green to purple and sickly lime. Above us, the nine niches glowed. They were no longer empty.

Standing in each was a withered old woman, so dried up and brittle they reminded me of mummies-except mummies don't normally move. Their eyes were dark purple, as if the clear blue water of their life source had condensed and thickened inside them. Their fine silk dresses were now tattered and faded. Their hair had once been piled in curls, arranged with jewels in the style of Roman noblewomen, but now their looks were disheveled and dry as straw. If water cannibals actually existed, I thought, this is what they looked like.

"What would happen to the nymphs?" said the creature in the center niche.

She was in even worse shape than the others. Her back was hunched like the handle of a pitcher. Her skeletal hands had the thinnest papery layer of skin. On her head, a battered wreath of golden laurels glinted in her roadkill hair.

She fixed her purple eyes on me. "What an interesting question, my dear. Perhaps the nymphs would still be here, suffering, waiting for revenge."

The moment she said that, I knew something bad would happen.

The next time that I got a chance, I swore that I would melt down Katoptris and sell it for scrap metal. The stupid knife never showed me the whole story. Sure, I'd seen myself drowning. But if I'd realized that nine desiccated zombie nymphs would be waiting for me, I never would've come down here.

I considered bolting for the stairs, but when I turned, the doorway had disappeared. Naturally. Nothing was there now but a blank wall. I suspected it wasn't just an illusion like I'd hoped it would be. Besides, I would never make it to the opposite side of the room before the zombie nymphs could jump on us.

Jason and Percy stood to either side of me, their swords ready. I was glad to have them close, but I suspected their weapons wouldn't do any good. I'd seen what would happen in this room. Somehow, these things were going to defeat us. It scares me. I'm not ready to tell them my secret. What would happen if Jason got angry at me? Would he leave me here? Would he break up our friendship? Would he forget about me and get together with Drew? I don't have time to think about these things right now. There are more important things at hand.

"Who are you?" Percy demanded.

The central nymph turned her head. "Ah . . . names. We once had names. I was Hagno, the first of the nine!"

I thought it was cruel that a hag like her would be named Hagno, but I decided not to say that . . . for safety purposes.

"The nine," Jason repeated. "The nymphs of this shrine. They were always nine niches."

"Of course." Hagno bared her teeth in a vicious smile. "But we are the original nine, Jason Grace, the ones who attended the birth of your father."

Jason's sword dipped. "You mean Jupiter? You were there when he was born?"

Zeus, we called him then," Hagno said. "Such a squealing whelp. We attended Rhea in her labor. When the baby arrived., we hid him so that his father, Kronos, would not eat him. Ah, he had lungs, that baby! It was all we could do to drown out the noise so Kronos could not find him. When Zeus grew up, we were promised eternal honors. But that was in the old country, in Greece."

The other nymphs wailed and clawed at their niches. They seemed to be trapped in them, I realized, as if their feet were glued to the stone along with the decorative seashells.

"When Rome rose to power, we were invited here," Hagno said. "A son of Jupiter tempted us with favors. A new home, he promised. Bigger and better! No down payment, an excellent neighborhood. Rome will last forever."

"Forever," the others hissed.

"We gave in to temptation," Hagno said. "We left our simple wells and springs on Mount Lycaeus and moved here. For centuries, our lives were wonderful! Parties, sacrifices in our honor, new dresses and jewelry. All the demigods of Rome flirted with us and honored us."

The nymphs wailed and sighed.

"But Rome did not last," Hagno snarled. "The aqueducts were diverted. Our master's villa was abandoned and torn down. We were forgotten, buried under the earth, but we could not leave. Our life sources were bound to this place. Our old master never saw fit to release us. For centuries, we have withered here in the darkness, thirsty. . .so thirsty."

The others clawed at their throats.

Wait, this isn't supposed to be happening. I can feel my throat closing up.

"I'm sorry for you," I said, trying to use my charmspeak. "That must have been terrible. But we are not your enemies. If we can help you-"

"Oh, such a sweet voice!" Hagno cried. "Such beautiful features. I was once young like you. My voice was as soothing as a mountain stream. But do you know what happens to a nymph's mind when she is trapped in the dark, with nothing to feed on but hatred, nothing to drink but thoughts of violence? Yes, my dear. You can help us."

Well that didn't go as planned.

Percy raised his hand. "Uh . . . I'm the son of Poseidon. Maybe I can summon a new water source."

"Ha!" Hagno cried, and the other eight echoed, "Ha!Ha!"

"Indeed, son of Poseidon," Hagno said. "I know you father well. Ephialtes and Otis promised you would come."

I put my hand on Jason's arm for balance."

"The giants," I 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."

I could tell he was scared.

"And you, Piper Mclean." Hagno's purple eyes glistened. "So young, so lovely, so gifted with your sweet voice. Keeping a dark secret from those you love. From you, we reclaim our beauty. We have saved our last life force for this day. We are very thirsty. From you three, we shall drink!"

How did she know about me? I can tell that Jason is staring at me with a puzzled expression.

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