“This is it, then.” Aaron’s voice wobbled as we looked down at the clear blue water. It was the first time I’d seen him look nervous about getting into the sea. Normally, he couldn’t wait! But then, normally, he wasn’t relying on a tiny glass vial filled with a magic potion to save him from fairly certain death.

  “Come on,” I said. For once, I was first to the edge. I took out my bottle and jumped into the water. The shock of that first touch almost made my heart stop. But I forced myself to duck down. Teeth chattering so hard that I thought my jaw was going to lock, I pulled the cork out of the bottle and tipped the fluid into my hands. As my tail formed, I spread the potion all over it. Please work. Please work.

  For a second, nothing happened.

  Neptune gave us the wrong thing! We’re going to die! I thought.

  But then I felt something change. I stopped panicking. It was working. My teeth had stopped chattering. My body warmed up. My tail flicked in the water. It had worked!

  Moments later, Aaron was by my side. “Phew!” he said. “Glad that part’s over.”

  We swam together to the other side of the fjord. The water was completely different from anywhere else I’d ever been. It was so clear it felt as if we were swimming through liquid glass, and the sea life was like nothing I’d seen before.

  Strange jellyfish shaped like angels, with orange heads and fluorescent bodies, flickered up and down with tiny wings; red starfish lay on the sand below us, grouped together in bundles like a collection of wishes; weird see-through blobs that looked like lightbulbs bounced toward us, bright-yellow skeletons lighting up inside their bubbly bodies. Huge flat rays with long tails skimmed the seabed, flicking their capes as they whizzed past us.

  And it was so quiet. Everything moved silently. The only sound was the swishing of our tails as we made our way to the mountains.

  Finally, we reached the other side. We pulled ourselves out of the water and sat on a small rocky beach while we waited for our legs to come back. My Arctic-ready snow pants returned with my legs, and I pulled my coat closer against the cold.

  Aaron stood up first. “Come on. Let’s see if we can find a way through this mountain,” he said.

  We trekked the length of the shore, looking for some kind of opening into the mountain. There were crevices all along the coastline, but we couldn’t see anything that seemed to go all the way through. All the caves were shallow. All the water trails ended in a wall. It was beginning to look as though we’d have to climb over the icy mountain after all, and I wasn’t sure I was up for that.

  “Can we rest?” I asked. I sat down on a large flat rock in front of one of the sea-filled crevices.

  “You’re right. It’s going to take all our energy to get up there,” Aaron said, sitting down beside me. “We should recharge our batteries first.”

  For some reason, talking about recharging batteries made me think about our shell phones. And the fact that I still hadn’t told him about giving mine to Shona. Maybe this was a good moment.

  “Aaron, I need to tell you something,” I said.

  “Really? Me too!” he replied. He looked oddly relieved. “You first.”

  “OK, so . . . um, you know how we were told not to tell anyone about this mission?”

  Aaron nodded.

  “Well, I haven’t told anyone all the details, but I gave Shona my shell phone.” I didn’t look at him in case he was angry. Instead, I went on quickly. “I’ve hardly seen her lately because we’ve been hanging out. And I miss her, and I didn’t want her to be mad at me, so I wanted to give her something. I —”

  “Emily.” Aaron put a hand on my arm. “It’s OK. I understand.”

  “It is? You do?”

  Aaron smiled. “Of course I do. We’ve got my phone, anyway. Neptune never needs to know.”

  I let out a breath. “Thank you. You’re so great!” I burst out before I could stop myself. Mainly to cover up my embarrassment at being so gushy, I added, “So, what about you? What’s the thing you have to tell me?”

  Aaron shuffled awkwardly on the rock. His cheeks had reddened and he wouldn’t look at me.

  “Aaron?”

  He fiddled with his hands in his lap. “Look, I’m telling you because I don’t want to keep anything from you, OK?”

  “OK,” I said nervously.

  “I didn’t think anything of it at the time, but just . . . well, some things have happened that have made me wonder, and now I don’t know what to think.”

  “Aaron, what is it?” I was getting really worried now. “Whatever it is, it’ll be fine.”

  “Promise?”

  Could I really promise? “Please, trust me. You’re scaring me.”

  “Look, it might be nothing . . .”

  “Aaron, just tell me!”

  “OK. Well, you remember the night of the concert?”

  Did I remember the night of the concert? The night we brought the human and mer worlds together? The night Aaron kissed me? It was only the best night of my life! I wasn’t going to forget that in a hurry!

  “Yes,” I said with a shy smile. “I remember.”

  “Well, just before the concert, I had a weird conversation.”

  “Who with?”

  “With Archie.”

  “Archie?”

  “I didn’t think of it as weird at the time,” Aaron went on quickly. “But . . . well, have you noticed he’s been acting a bit odd lately?”

  “Totally! What’s up with him?”

  “I don’t know. But it made me think again about that conversation. Especially with what Neptune told us — about our powers and everything.”

  “Aaron, you’re talking in riddles,” I said. “What are you trying to tell me?”

  Aaron kept fumbling with his hands and wouldn’t look at me as he replied. “He said I should kiss you.”

  “He what?”

  “He’d been teasing me about you for days, asking if you were my girlfriend and stuff.” Aaron’s cheeks had flushed so deeply they were almost purple. “I said I didn’t really know. He said there was only one way to find out — that if I tried to kiss you, I’d know for sure if you felt the same way.”

  “Go on,” I somehow managed to say through my tightly gritted teeth.

  “He kept going on about it, joking and ribbing me, asking if I’d kissed you yet. Then, on the night of the concert, he said that it was the perfect time to do it. He even bet me that I wouldn’t — said he’d give me ten bucks if I did.”

  I pulled myself up off the rock and moved away. I didn’t want to listen to this.

  Aaron got up and followed me. “Emily, wait!”

  I turned to face him. “You kissed me for a bet! There was me thinking what an amazing night it was — how romantic, how perfect — and all the time, you only did it to win ten dollars!”

  “It wasn’t really like that,” Aaron said.

  Wasn’t really like that? I wanted him to tell me it wasn’t at all like that. But he didn’t.

  “You didn’t do it because you wanted to,” I said. “You did it because Archie pushed you into it. Well, I hope he paid up.” I turned on him and started to walk away. I slipped on a stone as I turned and Aaron laughed.

  I stopped in my tracks. “And you think it’s funny?”

  “No. It was just. Well, actually, it is quite funny, if you think about it,” Aaron said. “I mean, I hadn’t gotten around to — you know — doing it till then, and I suppose Archie did make me think about it.”

  I stared at Aaron. “So you hadn’t even thought about kissing me till you were offered ten bucks to do it?”

  I thought back to how I’d felt, how I’d been wanting to kiss him for weeks. If it was possible to die of shame and embarrassment, I would have dropped dead on the spot. I did the next best thing. I glared at Aaron and turned my shame into anger. “The next time you’re offered cash to make a fool of someone,” I snapped, “it won’t be me.”

  “Oh, come on, Emily! It’s not the end
of the —”

  “I’m not listening.” I stomped off to the end of the scraggly beach and climbed some jagged rocks. How could he do that to me? How could he? And how could I have been such a fool? I’d thought we had something so special, and all the time he’d been laughing at me behind my back, kissing me for a bet!

  I clambered over the rocks, desperate to get as far away from him as I could. I didn’t want him to see my face — or the tears streaming down my cheeks. Angry tears. Not upset. Just angry.

  On the other side of the rocks, there was another inlet. The tide had gone out farther now and I clambered down from the rocks and paced across the pebbles.

  It was halfway across them that I noticed the cave: taller than me and about three times my width, carved into the rock by years of tides crashing against it, and only exposed now that the tide had gone out.

  I stepped inside it and peered into darkness. A few paces in, I was enveloped in the blackness — but the cave went on. Maybe it went all the way through the mountain. Maybe this was exactly what we’d been looking for!

  The last thing in the world I wanted to do right then was go back and talk to Aaron — but we still had to complete the mission. And the quicker we got it over and done with, the sooner we’d be back home and I wouldn’t have to have anything to do with him ever again.

  I climbed back over the rocks. Aaron was standing on the other side of them, throwing stones into the water.

  He turned and saw me. “Emily — please, let’s stop this. It’s stupid.”

  Great. Now he was calling me stupid on top of everything else. I swallowed down a furious response and tried to gather as much dignity as I could. “I don’t want to talk about it,” I said calmly. “I’m just glad that you’ve told me the truth, so I know where we stand.”

  He opened his mouth to reply, but I carried on before he got the chance to speak. “In fact, I don’t want to talk to you about anything except the mission. Let’s just get on with the job we’re here to do — and forget about everything else. OK?”

  Aaron just stared at me. I wondered what he was thinking. If he argued with me now, if he begged me to listen, told me it was all a big mistake, I would forgive him on the spot. If he didn’t — well, that would just confirm I was doing the right thing.

  Aaron sighed heavily. “OK,” he said.

  I hid my desperate disappointment. It was settled, then. I hadn’t gotten it wrong. Aaron had kissed me for a bet and it had meant nothing to him. Well, it was a good thing I knew. It was time to put it behind me and get on with our mission.

  “Good,” I said, clipping any emotion from my voice. “Now, follow me. I think I’ve found a way through the mountain.”

  We crept through the tunnel. Aaron led the way. The farther we went, the darker it got. If it hadn’t been for what had just happened, I would have held his hand but as it was, I kept my distance, zipped my mouth as tight as my coat, and plodded on through the damp, cold blackness.

  Just as I was beginning to wonder if we should give up and turn around, Aaron’s voice echoed back to me.

  “Look!”

  I peered into the murky darkness. What was I supposed to be looking at?

  “Ahead!” Aaron called. “Light.”

  He was right. I could just about see a tiny pinprick of light. Hope spurred us on and we sped up, trudging through the watery, echoey tunnel.

  Gradually, the pinprick of light turned into a small circle. Then it grew to the size of a basketball. Eventually, it opened up so much that we could see out. We’d done it! We’d gotten through the mountain!

  Once we were nearly out in the open again, Aaron turned to me. “We did it!” he said, coming toward me with his arms wide open.

  “What are you doing?” I said, folding my arms.

  He dropped his arms. “I thought we —”

  “Well, you thought wrong!” I snapped. “You think I’m just going to forget everything you’ve told me and go running into your arms as though it never happened? As though I’d ever trust you again?”

  Aaron just stood looking at me, his cheeks red as though I’d slapped him. I had to remind myself that he was the one in the wrong here, not me.

  “Let’s just get on with what we’re here to do,” I said more gently. “And forget the rest of it for now. OK?”

  Aaron nodded glumly. “OK.”

  We picked our way across the last bit of rocky ground at the tunnel’s entrance, to come out into the daylight. I rubbed my eyes and looked around.

  The view was utterly breathtaking. All around us, mountains stood majestically in the bright light of the afternoon. Their tops were sprinkled with snow, as though someone had carelessly tipped sugar all over them.

  A low cloud cut the top off one of the mountains, sitting above it like a hat. Another had waterfalls tumbling from about halfway up, where the snow ended, all the way down, splitting into five different channels so sharp and white they looked like forked lightning.

  And in the center of the ring of peaks — a lake.

  Around the base of all the mountains, the color of the rock was different. The whole bottom section was a deep reddish-brown. It looked like a tidemark, like the lake used to be much higher than it was now.

  We took a few steps toward the lake. I’d never seen such still water in my life. If someone had told me that it was actually a round mirror and not a lake at all, I would have believed them. Not a thing moved. The water lay silent; the mountains stood hushed and protective around it.

  High up, an eagle flew from a tree and came swooping toward us, as if checking on intruders. It came so close I saw its beady black eyes — and then it whooshed away again and the silence returned.

  I took a few more steps toward the edge of the lake and looked down. The mountains looked back up at me; the clouds floated perfectly still around them, like white fluffy islands in the sky.

  Aaron was beside me. “I thought the reflection was supposed to be different,” he said. “Neptune said it wouldn’t be the same as the reality.”

  I turned in a circle, examining the mountains, then looked back down. That was when I spotted it.

  “It isn’t!” I breathed. “Look.” I pointed at the reflection in the water. “See the two mountains there with all the snow — and then that huge tall one in between them?”

  Aaron followed where I was looking. “I see it,” he said.

  I turned and pointed up toward the mountains. “Now look,” I told him.

  Aaron gasped as he gazed where I was pointing. The two mountains were there, snowcapped exactly the same as their reflections in the lake. But there was no third mountain between them.

  “But that’s —”

  “Impossible?”

  “Exactly.”

  The third mountain — the one we could see clearly reflected in the lake — it didn’t exist.

  Which was when I knew without a doubt that we were in the right place.

  I stood at the water’s edge, looking down and trying to figure out how the reflection of the third mountain could be possible. The fact was — it wasn’t possible. And yet, it was here in front of our eyes. Not only that, but it had been predicted, too. Neptune had told us we would see this.

  So now what?

  Aaron was beckoning me over. “Em, you have to look at this.”

  I went to see what he was staring at. He pointed into the water right in front of us. “Look at my reflection,” he said.

  I followed his finger. His reflection was pointing right back at him.

  “What about it?” I asked.

  “Watch my eyes.”

  I looked at his eyes in the water. They were darting here, there, everywhere, looking around at the mountains, staring up from the lake into the blue sky above us, glancing this way and that.

  “Stop looking around so much,” I said.

  “But that’s just it. I’m not.”

  I turned to face him, and I watched him as he looked down into the lake. He was starin
g straight down at his reflection. I looked back at the Aaron in the lake; the eyes were still darting around everywhere.

  “But I don’t understand,” I murmured.

  “You try it,” Aaron said. “Try to look into your own eyes.”

  I looked straight down at myself — but I couldn’t meet my own gaze. My reflection’s eyes were darting all over the place, just like Aaron’s.

  “Remember what Neptune said about the lake?” Aaron asked. “He said you have to meet your own eyes.”

  “But we can’t,” I said.

  Aaron hesitated. Then he mumbled, “What if we hold hands?”

  Suddenly I was angry. “Have you done this?” I asked.

  “Done what?”

  I pointed at the lake. “This. It’s some kind of trick. Probably one that Archie taught you. I don’t know how you’ve done it, but if you think you can make a fool of me again, you can forget it!” I snapped.

  “Emily! Listen to yourself. You’re being ridiculous. Of course this isn’t a trick.” And before I could stop him, Aaron had reached out and grabbed my hand. I tried to pull away, but he held on too tightly.

  “Look,” he said. With his other hand he was pointing at the lake.

  Our reflections were shimmering, as though the water had been disturbed, ripples blurring the edges of our bodies. Nothing else in the lake moved.

  “Meet your eyes,” Aaron said.

  I looked down at myself. My image looked right back into my eyes. I stopped struggling against Aaron’s hand and turned to him. “Now what?” I asked.

  Aaron shrugged. “I don’t know. Why don’t we try doing it together? We each look into our own eyes at the same time?”

  “OK.”

  I met my eyes, staring down at myself, knowing Aaron was doing the same, and trying to ignore the feeling of a thousand butterflies fluttering in my chest. Within seconds, the eyes staring back at me turned black.

  “Aaron!”

  “Keep holding on,” he said firmly. “And keep looking.”

  I stared into the black holes where I should have been seeing eyes. The blackness grew, sending the water spinning as it did so. Soon it had taken over my whole face, then my body, then it joined with the blackness coming from Aaron’s reflection, too. Within a couple of minutes, we were staring into a spinning, fizzing black whirlpool that had stolen both our reflections.