“What do you mean? If they aren’t dreams, what are they?”

  Neptune flicked his tail and bent down so he was almost at eye level with us. He was so close I could see the white hairs of his mustache as they crept up his nostrils, and smell the herring he’d had for his lunch.

  And then, in a quivering voice that I would never normally have associated with Neptune, he said, “They are memories.”

  Aaron and I stared at Neptune.

  “Memories?” I asked.

  Neptune nodded. “I think so. Earlier this year, I undid the memory drug on this whole area, remember?”

  Of course we remembered. We’d been part of why he’d done it! Ever since then, people had recalled all sorts of mermaid memories that they’d forgotten about for years.

  “Even I was not immune,” Neptune went on. “It seems that there are now memories knocking on the door of my mind. There is something there, something that somebody has tried to hide from me, but it is returning — and it is wrapped in a dark threat.” He glared at both of us. “Your job is to find the threat and remove it — and find the culprit who tried to steal my memories in the first place.”

  Oh, was that all?

  “Your Majesty, forgive me for asking, but if this is so important and so dangerous, why aren’t you doing it yourself?” Aaron asked.

  “There is great danger ahead,” Neptune said. “To us all — and to the seas and the land. From my dreams — from my memories — I have a great sense that my presence on this mission would be a terrible mistake, and I cannot afford to make a mistake or to do the wrong thing. There is too much at stake.”

  He stopped speaking, but he wouldn’t look at us.

  “You’re scared!” I said.

  Neptune raised his chin. He paused for a long time. Then, finally, he lowered his head and uttered one quiet word. “Yes.”

  That small word was almost more frightening than anything else he’d said. The fact that there was something out there that scared Neptune meant that it should scare us all.

  I swallowed hard and tried to stop my tail from shaking.

  “I shall not say any more until I have your word,” Neptune said.

  “Our word about what?” asked Aaron.

  “Two things. One, that you are in this with me. And two, that everything you have heard today and anything you hear from me in the coming days will be between us, and only us.”

  He looked from me to Aaron, inviting us and challenging us at the same time. I didn’t look at Aaron. I didn’t need to. By now, I knew how his mind worked. It worked the same way mine did — was driven by the same things: excitement, danger, adventure. Even though it made me quake with so many nerves my scales were standing on end, I knew what my answer would be — and I knew Aaron’s would be the same. I’d have to think of a way to get Mom and Dad to agree — but we’d deal with that when the time came.

  Without even a glance in each other’s direction, Aaron and I replied in unison.

  “We’re in.”

  It all happened really quickly after that.

  Neptune flicked his trident and called out to his dolphins. A moment later, they returned to the cave.

  “Come,” he said, beckoning us to join him in his chariot.

  The dolphins sped us out of the cave, through all the winding tunnels we’d been brought down blindfolded earlier, and up into an area so grand it couldn’t have been mistaken for anything other than one of Neptune’s palaces. Giant pillars that seemed to be made of solid gold stood in each corner. Jewels filled the rocky ceiling. Light bounced around, dazzling my eyes as much as the chariot ride had dazzled my mind.

  Even the fish that weaved around us seemed to swim with an air of importance. A lionfish that looked as if it had put on its grandest outfit glided across the atrium looking as regal as a duchess. Jet-black fish with serious faces and sharp beady eyes swam by without glancing our way, aloof and superior.

  We wound our way through the grand entrance hall to an enormous pair of doors. With a flick of his trident, Neptune called, “OPEN!” and the doors drew apart.

  A moment later, we were back out in the open sea. The water was dark and murky after Neptune’s palace, and I rubbed my eyes. Neptune indicated for us to leave the chariot. We slid over the side and flicked our tails, treading water as he explained where we were and how to find our way home.

  Then he said, “Come to the palace gates at six o’clock tomorrow morning.”

  Six o’clock in the morning?

  “You must be there when I awake. I need to tell you my dreams as soon as my eyes open. I don’t want you to miss anything. Do you understand me?”

  We nodded.

  “Good. Then I shall see you in the morning.”

  “What will we tell our parents?” I asked.

  Neptune turned his dark eyes on me. “You’ll think of something.”

  Aaron cleared his throat. “How will we —”

  “The dolphins will bring you,” Neptune said impatiently. “Come to this point here, and they will meet you — at six precisely. The dolphins know where to find me. They will bring you to my side. I wake at half past six. You will be there. No one else must know where you are, or why you are there. I repeat — no one. We are clear on this?”

  “Yes, Your Majesty,” I said.

  “Totally clear,” Aaron added.

  “Very well,” Neptune said, turning away from us and flicking his trident to give the dolphins their orders. “Until tomorrow.”

  A second later, we were dismissed and Neptune, the dolphins, and the chariot were gone.

  Aaron and I hovered in the murky water for a little while without speaking. It was hard to know what to say.

  Below us, thick green tubes of seaweed brushed against dusty-pink coral as it swayed in the current. Fish of all shapes and sizes swam toward us, around us, away from us, taking a peek before deciding we weren’t all that interesting and darting away again.

  We started swimming in the direction Neptune had told us. We swam in silence most of the way. I was busy going over everything that had happened and trying to make some sort of sense of it all. I guessed Aaron was doing the same.

  Finally, when we were still quite a way from Brightport, Aaron slowed down and turned to me.

  “You OK?” he asked.

  “I don’t know,” I replied honestly. “You?”

  Aaron tried a wonky smile. “I think so,” he said. “I’m glad we’ve got each other at least.”

  I smiled back. “Me, too.”

  “What are we going to say to our families?” I asked.

  “We could say we’re meeting up to swim to Rainbow Rocks and watch the sunrise together?”

  “Good idea. That way they won’t ask too many questions.”

  But as we approached Brightport, I couldn’t stop my mind from asking its own questions. What if we couldn’t fulfill Neptune’s mission? What if we got hurt — or worse?

  “Hey, slowpoke. Race you to the Brightport pier!” Aaron called from ahead of me, breaking into my thoughts before they spiraled out of control.

  “You’re on!” I pushed the questions to the back of my mind, flicked my tail as hard as I could, and sped through the dark water.

  The next morning, when my alarm clock went off at half past five, I leaped out of bed thinking there was a fire. Then I remembered — it was worse then a fire. It was a date with Neptune and his nightmares.

  Aaron was outside the boat as soon as I closed the door behind me. “Ready?” he asked.

  I laughed drily. That was about the best I could manage as a reply.

  We set off for the open ocean.

  About half an hour later, we reached the palace. The dolphins were waiting for us outside the doors, just as Neptune had said they would be. We climbed aboard the chariot and they took us inside.

  Twenty twists and turns and fifty chandeliers later, we arrived at an arched door with a golden doorknob and a sparkling trident on the front, built into a rocky
wall. The dolphins pulled to a halt.

  “I guess this is our stop,” I said.

  We clambered down from the chariot and the dolphins turned and swam away. We were alone, outside Neptune’s room.

  Aaron decided to be the brave one. Gently turning the knob, he pushed against the door. It opened. We swam inside.

  It was the biggest room I had ever seen, anywhere. It was perhaps the size of a big stage in a theater — and about as dramatic. The room was full of weird and wonderful furniture: a chaise longue in the shape of a giant lobster, an enormous cushion that looked like purple silk but could just as easily have been a giant eel wrapped around and around itself, coral-covered rocks lighting up the floor below our tails, a curtain of falling water across the center of the chamber.

  We swam across the room looking for Neptune. We could hear him; the snores sent vibrations through the whole place so hard that it made my teeth rattle. They were coming from the other side of the waterfall curtain. We swam toward it, pushed through it — and stopped.

  On the other side, we saw Neptune. At least, we saw bits of him. He was lying inside something that could have been a piece of furniture — the grandest, largest piece of them all, an amber bed, with Neptune on the inside, and eight pillars around him, twirling upward and tailing into a spiral above him. The pillars began to move and twitch as we approached — which was when we realized that they weren’t pillars. They were —

  “An octopus!” Aaron blurted out. “Neptune sleeps on an octopus?”

  I looked again, and just about managed to stop myself from turning and swimming straight out of there and never coming back. It looked so similar to something I’d seen before, and never wanted to see again. The kraken. Neptune’s special pet. The one I’d woken early from its hundred-year sleep. The one that nearly destroyed a whole island, not to mention a cruise ship full of people — including my mom.

  But Aaron was right. This wasn’t the kraken. Its tentacles weren’t filled with slime and goo and disgusting purple suckers. They looked, like everything else around here, as though they were filled with jewels. Triangles of light bounced off the suckers as they wafted with the movement of the water. No, this was just a harmless, innocent — enormous — octopus, which happened to serve the role of being Neptune’s bed.

  I had begun to think about the possibility of relaxing a little when Neptune suddenly let out a roar.

  “NOOOOOO! You will not!” he shouted. “The water! Fetch the water! I’m cold. So cold. Quick, catch the water. Catch it! Before it’s too late! Before it . . .”

  What was he talking about?

  A wave suddenly grabbed me, rolled me around like a snowball, and hurled me across the room. The room was shaking. The walls vibrating. The chandeliers jangling. What was happening?

  Another, more violent, wave picked me up and threw me again. This time I landed next to Aaron. He was holding on to a dagger-shaped stalactite on the ceiling. He held out his other hand to me. I scrabbled through the current and reached out. Missed. Tried again, but got caught in a whirling current that spun me around as if I were an old pair of jeans on a spin cycle.

  Finally, I lunged against the tide and grabbed Aaron’s hand. Instantly, the water calmed. The spin cycle stopped. The room quieted and stilled. A minute later, it was as if it had never happened. Was Neptune right about us still having his power? Had we stopped his storm with our hands? Or had the storm merely worked its way out and finished of its own accord? I didn’t have long to think about it, as Neptune had woken up.

  We swam across the room to see the giant octopus slowly unfurl itself as Neptune sat up inside it, his tail draped lazily in between two of the octopus’s tentacles.

  “You came,” he said simply.

  “You ordered us to,” I pointed out.

  Neptune half smiled. “Quite. Well, then. On to business. Let me tell you about my dream.”

  “Business” was basically listening to Neptune talk for an hour, and trying to pick out the parts that . . .

  a) made any sense;

  b) might help us figure out how to prepare for our mission;

  c) gave us some indication about the minor details, like, oh, you know, where we actually needed to go.

  Unfortunately, there wasn’t much of any of these. From the pieces we’d overheard Neptune shouting in his sleep, and from what he told us when he woke up, this was what we had figured out so far . . .

  Wherever we were going, it was cold, really cold.

  There was something to do with water.

  And possibly mountains.

  And that was about it.

  It was the same thing the next day: Neptune screaming out in his sleep, a brief but very violent storm, and an extremely limited amount of helpful information.

  By the third morning, I was starting to feel exhausted from waking up so early every day. On top of which, it felt as if we weren’t getting anywhere.

  That afternoon, Aaron and I were hanging out on Fortuna, going over the things Neptune had told us and trying to find some way to piece it all together. It felt as though he’d given us a bag full of jigsaw pieces and told us to make a picture — except the pieces didn’t fit together. They didn’t even seem to be part of the same puzzle!

  Mom was getting ready to go to her Pilates class when she burst into my bedroom, leggings on, sweatband around her head, tracksuit jacket around her waist. “Emily, darling, would you go over to Millie’s for me? I’ve torn a hole in my gym socks and can’t find the needle and thread anywhere. I’m sure she’ll have some. I’d go myself but I have to stay and finish my book before tonight’s book group.”

  I didn’t bother to make any comment on Mom’s ridiculously packed social life — or equally ridiculous outfit.

  “Of course,” I said, and Aaron and I headed over to King, Millie’s boat.

  I climbed aboard and pushed the door open. “Millie!”

  No reply. We were about to leave when I heard something. She must have been down on the lower level. She’d had the boat adapted so that her boyfriend, Archie, could visit. He’s one of Neptune’s closest advisers, and a merman. The lower section of the boat had trapdoors like ours, so you could get to it from above or below.

  I opened up the trapdoor and was about to shout down, when I saw who had made the sound. Archie.

  “Oh,” I said.

  He turned around. “Oh, hi, Emily!” he said, with a big smile, which seemed false to me. Not that Archie doesn’t smile much — just, well, he doesn’t usually show all his teeth when he does. He looked like a dog flashing its fangs at an intruder.

  “I was just, er, just leaving,” Archie said. “Just stopped by to see if Millie was here. I was going to surprise her. Take her on a date. You know, being spontaneous and all that. But — well. She’s not here, so, bye, then. I’ll tell her you came over.”

  And before I had a chance to reply, he was gone. I stood there, holding the trapdoor open, staring down at the empty deck for a few moments, wondering if it was my imagination or if that had been a little weird.

  “Is she there?” Aaron called from the door.

  I went back to join him. “Nope. Just Archie. He’d come to take Millie on a surprise date,” I said.

  “Aww, they’re so romantic, those two.”

  Aaron was right. Archie probably wasn’t being weird. He was always doing sweet things like that. All this scheming and secrecy with Neptune was making me paranoid.

  “My mom will have some thread, I’m sure. Let’s go over to my place,” Aaron said.

  We left King and headed over to Aaron’s house.

  It was on the fourth morning that we finally had a breakthrough.

  The storms hit us on the way to the palace. “Are we late?” I asked as we battled against the swell.

  Aaron shook his head. “He must be waking early.” We were spun around and washed against rocks all the way. By the time we arrived, we were both a bedraggled mess. The dolphins picked us up at the gates, as usual,
and sped to Neptune’s quarters.

  Neptune was reclining on the lobster-shaped chaise longue. He beckoned us into the room and we nervously swam toward him.

  “Sorry we’re late,” I began. “We got caught in —”

  “It doesn’t matter,” Neptune said. “You’re here now.” He smoothed his beard and spoke quickly. “My dreams were especially vivid this morning — such strong visions that I know without question these are memories. The places I visited — it was as though I were there. Look!”

  He held out his hand. “Touch it,” he said.

  I felt his hand. It was like ice. “Youch!” I said, pulling my hand away.

  “You see? It’s real!” Neptune exclaimed, his eyes wide and wild. “It’s coming for me! It’s in me!”

  By now, we’d become used to him talking in riddles, so we didn’t interrupt.

  Neptune leaped off his chaise longue and began to swim around us. He flicked his tail as he swam, and a line of bubbles followed him in a wavy trail. “I felt the ice. I saw it — saw where it had come from,” he said. “There is a lake — it has something to do with the memories — a lake where you must meet your own eyes and jump. And there is water — frozen at the top of a mountain. You must find this water. Only you can hold it. You must do that. You understand? And you must find the lake. Do this and you will also find the threat — and the traitor.”

  He stopped swimming and, gripping his trident, stared into our eyes. “Above all, I finally know the most important thing. I know where it is. I know where I am sending you.”

  Aaron swallowed. “Where?” he asked shakily.

  Neptune lowered his voice and leaned in close. Almost in a whisper, he said, “To the Land of the Midnight Sun.”

  The Land of the Midnight Sun? Where on earth was that? We stared at Neptune openmouthed, waiting for him to explain.

  The only trouble was, he didn’t.

  “We haven’t got long,” he went on hurriedly. “You’re leaving this weekend.”

  “This weekend?” I gasped. “As in, four days’ time?”