I stumbled away from the bench, stuffing the newspaper in my pocket, out of sight.

What was I going to do? Where could I go? I couldn't stay in Brightport. Sooner or later, someone would recognize me from the photo and reel me in to claim their reward. My worst nightmare really was going to come true.

I walked along in a daze, convinced that every person I pa.s.sed was staring at me. Had they bought their morning paper yet? How long would it be before I was caught and dragged up in a net to be displayed for the whole town's entertainment?

There was only one answer to my questions: I had to get away. I had to go to the sea.

I turned toward the beach. Right now I felt like I never wanted to set foot on dry land again. So much for bringing the two worlds together!

I hurried down to the beach and cast a quick look around, then ran to the point below the pier where I could slip into the water unseen.

Except someone was already there.

"Emily!"

I spun around. Mandy! She'd come to sneer. Now I knew she was the one who'd done this. I didn't know how, but there was no other explanation. It had to be her.

"What are you doing here?" I snapped. "Come to gloat, have you? Had your fun and now you want to see the effect it's had? Well, congratulations. You've done a great job this time!"

Mandy stared at me in astonishment. "I don't know what you mean," she said.

"I'll bet you don't! All those people seeing mermaids - funnily enough, since my conversation with you." I grabbed the newspaper from my pocket and shoved it in her face. Mandy scanned the front page.

She looked up at me. "Emily, I don't -"

"And a photograph - of me! Page two," I said.

Mandy opened the paper and squinted at the photo. "How do you know it's even you?" she asked. "Emily, no one would know who it is. You can hardly even tell it's a -"

"Well, I know who it is. And you know who it is. And soon enough, the whole town is going to know."

Mandy closed the newspaper and stared down at it. "Emily, I didn't have anything to do with this," she said. "You and I - yesterday, we were friends. Well, we made up ages ago. But yesterday I remembered. Do you have any idea how happy I was when I woke up this morning?"

I thought back to how I'd felt when I woke up, in those few minutes before everything had gone wrong yet again.

"Not just because of you and me being friends again," Mandy went on. "That wasn't the only thing I remembered. I remembered how it had felt when we saved all those people from the kraken. I remembered what it feels like to be nice. To do good things, to make people happy!"

I looked at her. She was smiling. Not her sneering, snarly smile. Her real one. The one that I hadn't seen much of for years. "You really didn't have anything to do with this?" I asked.

"I really didn't," she said. She drew a cross over her chest. "I promise."

I slumped down on the sand. "Well, why did it happen, then?"

Mandy joined me. Picking up a handful of sand and letting it run through her fingers, she said, "Maybe it's got something to do with you and Aaron."

I stuck my feet into the sand. "What d'you mean? Aaron would never do anything like that."

"That's not what I meant." Mandy turned to face me. "All these people have remembered since you and I became friends again, right?"

"Right," I agreed.

"And how did you make that happen?"

I looked down. I still didn't know if I could trust her, but I didn't exactly have much to lose.

"Neptune has this thing called a memory drug," I began. Then I told her about the verse, and why it meant that Aaron and I could overturn Neptune's magic when we held hands.

"That's it, then!" Mandy jumped to her knees, her eyes wide with excitement. What exactly there was to be excited about, I wasn't so sure.

"That's what?" I asked flatly.

"You undid the memory drug!"

"That's what I just told you," I said. "That's why you remembered we were friends when Aaron and I held hands."

"Not just on me! You undid the memory drug on the whole town of Brightport!"

"I - we -" I began. Then I stopped and stared at her. Of course! As soon as she said it, I realized that it was the most obvious thing in the world. So obvious that I hadn't even thought of it!

Aaron and I must have been even more powerful than we'd realized. Mandy was right. It was the only answer that made sense.

"One thing I don't understand, though, is why there are so many mermaids around here," Mandy said.

"Shiprock," I said simply.

"Ship what?"

"It's a mermaid town," I replied. "There aren't many mermaid places near where humans live, but this one is close by, so it's quite risky. I guess there've been a lot of accidental sightings over the years."

Mandy looked as though she were going to say something. For a second, I thought the old Mandy was going to come back and laugh in my face. But she didn't. She just nodded.

"What are you going to do?" she asked after a while.

What was I going to do? All I knew for sure was that I had to get away from Brightport. My first thought was to head for Shiprock, but I wasn't even welcome there now! Then I remembered I was supposed to hang out with Shona today. It was Sunday - the day we said we'd go out looking for the lost sirens.

I leaped up. The lost sirens! Maybe I could hide away with them!

I shook the sand off my clothes and headed down to the water's edge. Mandy was behind me. "What are you doing?" she asked. "Where are you going?"

"Look, just cover for me, will you? Tell my mom I forgot to tell her I was spending the day at Shona's. I had to get going and I didn't want to wake her."

Mandy nodded. "So you'll be gone all day?" she asked. She sounded disappointed. I'd be out at least all day, I thought. This problem wasn't going to have gone away by tomorrow. But I'd worry about that later. At this point, all I wanted to do was hide.

"Yeah," I said.

"What about Aaron?"

"Tell him I've gone to see Shona and I'll catch him soon, OK?"

"OK." She turned to walk away.

"And, Mandy?"

She turned around. "What?"

I smiled at her. "Thanks. I like being friends again."

She held my eyes and nodded. "Yeah, me too," she said.

And with that, I glanced around one last time, whipped off my sandals, and slid into the sea.

"So the whole town knows about you?" Shona asked as we swam along. I'd filled her in on the news in Brightport, but I didn't want to tell her about Aaron - yet. I felt weird keeping a secret from Shona, but I felt even weirder telling her that Aaron and I had a special power - stronger even than Neptune!

"Well, not exactly about me," I said. "At least, I hope not." Maybe it would blow over soon. People would throw their newspapers out in a few days and forget all about it again. The picture was pretty blurred, after all. Perhaps it would be safe for me to return in a couple of weeks.

Yeah, and perhaps sharks would walk across the moon.

I might as well get used to the idea of living as a recluse.

We swam on, gliding over pastel-pink bushes and lime-green rocks. Sea urchins littered the seabed, still and spiky like curled-up hedgehogs. Black wavy rays with fins like Dracula's cloak pa.s.sed beneath us, tickling the sand as they slid by.

"Miss Merlin told us a bit more about the lost sirens," Shona said as we swam.

"What did she tell you?" I asked, glad for a change of subject.

"She thinks she knows roughly where they were last seen. She said that after cla.s.s last week, she looked into it more and she figured out some coordinates that no one's ever worked out before, so I put them into my splishometer."

"And? What did it tell you?"

"It's about five miles away - hardly any distance," she said, so excited that her eyes looked about ready to pop out of her face.

I thought about Brightport - people waking up and buying their local paper, all eager to catch a mermaid and win a reward. My photograph on page two. I shuddered and swam ahead. "Come on," I said. "What are we waiting for?"

It felt as though we'd been swimming for hours. The sea had grown colder and deeper and darker. Lone, sleek, gray fish slid by, weaving among seaweed that trailed up from the seabed. Shoals of flat round fish swam toward us and then away again, flickering like mirrors in sunlight as they flashed by.

Ahead of us, below, all around us, sea life went about its business, oblivious to the two intruders swimming all around looking for something that might be no more than an ocean myth.

A lion fish with ornate markings around its jowls stared through us as we pa.s.sed. A dancing crab with stick-thin legs jiggled sideways across our path. Ferns opened and closed with the rhythm of the sea. We swam on.

"Are you sure you put the right numbers in?" I asked. "We must have swum more than five miles by now."

"It's got to be around here somewhere," Shona said, consulting her splishometer. "Unless Miss Merlin got it wrong."

Which I was starting to think she must have. I didn't say anything, though. Shona loves an adventure more than anything, and I didn't want to take it away from her. And anyway, I didn't have anything better to do. There was no way I could go back to Brightport yet, and I wasn't exactly welcome in Shiprock. The best thing I could do was find the lost sirens and plead with them to let me be lost with them.

"How about we split up?" I suggested. "You go that way." I pointed over to my right. Long, thick trails of seaweed stretched up like thick ropes. "I'll go this way." To my left, pink spongy fingers reached upward, open and outstretched as though they were silently begging. Deep, jagged rocks lay all around us, purple and green twigs and sticks littering every crevice. "Give it ten minutes and then meet back up again," I said.

Shona pointed to a moss-covered rock with a tree growing horizontally out from its side. "Meet you over there," she said.

"Ten minutes," I repeated.

Shona nodded. "Good luck."

Shona swam away to the right, and I swam off the other way.

Please let me find them, please let me find them, I thought as I swam, scanning every bit of rock and seaweed I could see, just in case there was a secret entrance hidden inside it. Please don't make me go back to Brightport till it's safe.

I swam across reeds like bunches of thick-cut spaghetti, big leafy plants like giant cabbages, bright red rocks, shining like mottled marble. A long eel, green with white spots, slithered in and out of the reeds, poking its head into holes, then slithering out again and slinking away. Two round fish smooched past in a perfectly synchronized dance. Everything moved slowly along. Nothing was in a hurry down here.

And there were no lost sirens, either.

I was about to head back to meet Shona when something stopped me.

A current was tugging at me. It reminded me of what happened at Allpoints Island if you swam out too far and got caught in the Bermuda Triangle. A shiver flickered through me like a wriggly fish squiggling through my body. What was it? Where was it taking me?

But this wasn't like that current. It wasn't dragging me out anywhere; it was hardly pulling at all. It felt more as if it were leading me somewhere, directing me, helping me. I wanted to follow it!

I let go of my resistance and let the current do the work. Soon I was zooming through the water, racing against a stripy yellow-and-black fish, whizzing past trails of fern and weed.

And then the current slowed. The sea had turned darker, and colder. The fluttery feeling came back. What was I doing, floating along on a current that had led me this far down? I hadn't even looked where I was going. How was I ever going to get back and find Shona again?

And where was I, anyway?

I looked around. The current had pulled me to the top of a circle of tall rocks. I couldn't see the bottom of them, but they were grouped around a dark hole, like an enormous well. I swam to the edge of the well and looked down. It was foaming and rushing with water that poured down like an underwater waterfall.

I could feel the current again. It was lifting me, edging me closer to the top of the well. It seemed to be teasing me, daring me to go down. Should I? Could I?

Before I had time to decide, the current nudged me right to the edge of the well. A moment later, I was hurtling over the top, into the waterfall.

Water rushed at me from every side, turning me over and around, pulling me farther and farther down, dragging me ever closer to the bottom of the sea. I tried to fight against it, tried to swim upward, but it was impossible. The current was dragging me lower and lower, throwing me down faster than anything I'd ever known. It was like a rocket - only heading down, toward the seabed.

Eventually, I gave in and let it pull me. And then, before I knew what was happening, it stopped.

Bedraggled, exhausted, and disheveled, I had landed - in a dark, enclosed, rocky hole at the bottom of the ocean.

I glanced around, my eyes gradually adjusting to the darkness. There were rocks on every side of me. I was at the bottom of the well. The weird thing was, the rushing water had stopped. All I could see was clear water leading all the way up - so clear I could see right to the top. It looked like an awfully long way up.

Where had the waterfall gone?

I tried to swim up the well again, but an enormous force stopped me. I kept on landing back in the same spot, shoved back down. The waterfall's force was still there, but with no rushing water. Impossible - but real. It was like a magic trick.

Then there was a sound of movement from somewhere nearby. I whizzed around to see where it had come from. That was when I noticed that one side of the well had a hole in it, just big enough to swim through. A bunch of seaweed hung down from the top of the hole, like thick cord. I pushed through it and swam out of the well.

I found myself in a larger opening. Above me, the ceiling was smooth brown stone. Below, the sandy floor slipped away, sloping gradually downward. All around me, the walls were lined with stony, jagged pillars and arches and caverns. Trails of multicolored seaweed dangled here and there like Christmas decorations. Behind them, I heard the swishing sound again. In the growing light, I saw a tail flick sharply.

"Shona!" I cried in relief, swimming toward the tail.

But it wasn't Shona.