The day passed in a blur of Earl Grey, beans on toast, and several games of canasta. I moved along through it as though I were walking through fog. And in a way I was. The mist all around us seemed to have totally clouded my thoughts. Or perhaps it had more to do with the fact that the whole world as I knew it was collapsing around me. The sadness Mr. Beeston had left me with felt like a physical weight dragging me down.

  The night wasn’t much better. It was filled with dreams about my parents and about the castle. In one, I was swimming toward it as hard as I could. Mom and Dad were waiting for me there, but it kept getting farther and farther away. With every stroke, it became more distant, but it was calling me, willing me to find a way to get there. All around me, voices were urging me on. Then the ring on my finger turned into a knife and cut through the sea so that I could walk there — but I had no feet. My tail flapped lifelessly on the ground for a moment, till the ring shone a beam that lifted me and carried me toward the castle. I almost reached it — it was inches away. And then I woke up.

  Panting and sweating, I got up and looked out through my porthole. Directly ahead of me, the castle loomed just as it had in my dream, the mist flowing around its middle like a skirt. Its windows were black, and closed like sleeping eyes. But as I stared, they seemed to brighten, shining at me, just at me. Blinking and glinting, it was as though they were spelling something out in a code I had yet to crack. I knew one thing for certain, though. I had to get to the castle.

  It was early, too early for anyone else to be up. Even the sun hadn’t risen yet. The sky was a deep purple. I crept out onto the deck and looked around. In the distance, the castle was almost hidden by the mist. Just the turrets were visible, reaching upward, tall and dark and forbidding.

  As I looked across, my chest burned. The ring was tight on my finger, the diamond smooth and bright. What is it? I asked silently. What do you want?

  The ring didn’t reply. Well, no, it was a ring. But as I closed my fingers around it and breathed in the salty air, I knew I had to try again. My dream had been telling me that there was something waiting for me at the castle. I just knew it. The thought was too strong for me to ignore. I had to get there, and I had to go now. If I waited any longer, Millie would be up, and there was no way she was going to let me out of her sight again. And it wasn’t fair to keep dragging Shona off on my crazy stunts. I’d already gotten her into enough trouble. No, let her sleep.

  I slipped into the water as quietly as I could. The sea rippled around me as my legs jerked and twitched, stiffening, sticking together, and finally stretching out to form my tail. What there was of it. Again, patches were missing all over. Fleshy white bits of my legs poked through the scales. As I moved, my tail felt taut and tight. It didn’t bend right. It was getting worse.

  Never mind. Just get there. Determination drove me on, and I ducked my head under the water and swam.

  But it was just like last time, and just like my dream. The more I swam, the farther away the castle seemed to be.

  I plowed through the water as hard as I could, thrashing my tail with every bit of energy I had, stretching my arms as wide as they would reach, pushing myself farther and faster with every stroke. But it was useless. I was getting nowhere.

  Below me, the sea looked dark and unwelcoming. Jagged rocks were piled on top of each other as though they had been dumped there and forgotten long ago. Small pockets of sandy seabed were dotted about in between. Tiny black fish darted away as I swam across them. A round yellow fish slid slowly in and out of the crevices like a submarine.

  I came to the surface to catch my breath. I didn’t seem to be able to stay under water as long as usual. That must be the curse too. Where would this end?

  No, I couldn’t think about that or I’d end up giving up altogether. I couldn’t think about anything. I just had to get to the castle. But it was as far away as ever.

  As I flicked my tail to tread water, I looked at the ring. “What do I do?” I said. And this time, it did reply. Not with words, but with a feeling, the way it had before. A feeling that seeped through me like heat filling my bones. A feeling of trust. I had to trust the ring. Just like in my dream, if I gave in and let it guide me, it would get me to the castle.

  So I did. I stopped trying. I stopped swimming, stopped pushing myself to get there faster or sooner — and instead I listened to the ring. It felt as though I were tuning a radio: finding the right station and getting it clear and sharp.

  I held my hand out in front of me, letting the ring guide me. Immediately the water became smoother; a gentle current started to glide me along. With the slightest, tiniest flicks of my tail, I zoomed forward. Heading toward the castle.

  At last, it was coming closer! Soon the current slowed. The water seemed to grow thicker, and colder, and much darker.

  Below me, a shoal of silver fish swirled down like a light beam, flashing briefly through the black sea. In their wake, a group of manta rays slowly flapped their long capes as they slithered by. I kept well out of the way, watching from behind a rock till they’d passed.

  Ahead of me, the sea looked even blacker. As I got closer, I could see a big dark hole, a tunnel. Sharp rocks formed a ring around its entrance.

  The strangest fish seemed to pace across the tunnel’s entrance, gliding heavily and slowly. Five or six of them. I knew what these were. I’d never seen one in real life, but we’d studied them in Aquatics and Animals: humphead parrot fish. Almost twice as big as me, they looked like big, burly bouncers wearing silly masks and rubber shields. Their bodies were gray, with a purple splotch of paint in a line up their heads like war paint. These fish had jaws you didn’t want to get in the way of. Each time one of them passed the tunnel’s entrance, it opened its enormous mouth and took a bite at the rock, dissolving it into soft sand. A tiny beach lay around the entrance.

  My tail shook. The castle lay beyond this tunnel. I knew it.

  I waited for ages, counting the seconds in between each sweep of the tunnel’s entrance until I’d worked out the best time to go. One more parrot fish passed the entrance — and then it was open. This was it. They were all facing away, swimming to opposite sides. Any second now, one of them would turn and swim back. It was now or never. And never wasn’t an option.

  So I darted into the tunnel.

  It was so cold in there, and so dark. And I felt so alone. Every now and then, I passed something. Thin black fish swam in single file along the sides of the tunnel, coming from behind and overtaking me. Thick, chunky silvery-blue fish flopped by in pairs, swimming toward me and sailing over my head. Trails of seaweed hung from the walls, waving with the current and making me jump when they brushed against me.

  I swam on.

  The tunnel twisted and writhed about like a giant snake. Around the next corner, around the next corner, I said to myself again and again. It had to end sometime.

  And then it did.

  The tunnel led upward, growing lighter and warmer with every stroke until I emerged, panting and breathless, in a round pool. I took a few seconds to catch my breath as I glanced around. Where was I?

  I swam all around the edges of the pool. The walls were gray rock and covered in green algae; chunks of bubbly seaweed hung down into the water like bunches of grapes on a vine.

  Above the water, the pool was enclosed by walls. Gray, lumpy, dark, and cold, dripping with dampness, it was like a long-forgotten cellar, with a metal door in one corner.

  I’d done it. I was in the castle. In a cellar. On my own.

  What was I doing?

  I shivered as I pulled myself out of the water and waited on the side, watching my tail flicker halfheartedly, flapping on the surface of the water as it faded away. My legs slowly emerged, numb and tingling. This time the numbness in my feet didn’t go away. I looked down. Webbed. Even more so, like my hands.

  I didn’t have time to think about that, or about any of the fears I could so easily have thought about if I gave myself half a chance. Just one q
uestion remained: why was I so sure the castle offered me something? I tried to bat that question away with the rest of my dark thoughts. Whatever the castle wanted with me, I had to find out and get back to the boat. The others would be up soon.

  Edging around to the doorway, I felt for a handle. A brass knob turned slowly, creaking like an ancient floorboard as I twisted it. Despite the creaking, it turned easily enough, and I opened the door.

  I inched my way up a spiral staircase, gripping a rope handrail for support. Around and around, the stairs climbed steeply and tightly. I felt as though I were climbing into the clouds, floating upward. By the time I reached the top, I was dizzy and disoriented. Another door. This time I held my breath and turned the knob as slowly and gently as I could.

  I was in a corridor, wide and long, with pictures all along the walls. Battle scenes, shipwrecks, storms at sea; the kind of thing you always see in castles like this.

  I almost laughed at myself. Castles like this? How could I even think for a moment that this was like anywhere I’d ever been?

  I mean, yes, from the inside it looked a little like the kind of place you might see in a book or on a documentary or something. But there was something different about it too. Aside from the fact that it seemed to float on a mist in the middle of the ocean, something about it felt unreal — like a film set or a cartoon. I couldn’t put my finger on it, exactly, but it was just a tiny step removed from reality. As I moved along the corridor, I felt a little like an actor in a film where everything else is computer-generated animation. Unreal.

  I kept glancing at the pictures to see if anything had changed while I wasn’t looking — whether the boats had moved or the storms had raged. They hadn’t. Of course they hadn’t. I was imagining it. I must be.

  I crept on down the corridor. Ahead of me, another door lay open. I went in.

  It was a smallish, box-shaped room, jam-packed from floor to ceiling with dusty books in fancy bindings, all bronze and gold. The titles were full of words I could hardly read. Most were foreign; a few were English. All looked hundreds of years old. Not exactly your light bedtime reading.

  Then I noticed the window. A large rectangle that covered half of one side of the room, it was set into a recess with a small bench. I sat on the bench and looked out. The sea stretched for miles and miles, all the way to the horizon, just as it did from Fortuna. But down below, waves lapped on rocks that were gradually surfacing like bared teeth as the tide edged out. It was as though the castle stood on a podium above the rest of the world, separate from the world, floating above it as though in a dream. What was this place?

  Another door took me out of the library into a smaller room. One side of the room was filled with weapons. Opposite, the wall was covered in silk banners painted with flags from all over the world. I recognized some of the shapes and colors from geography lessons back in Brightport. Others were completely unfamiliar. There was even a skull and crossbones on one flag.

  I moved on quickly. The room led out to another corridor. More paintings on the walls, this time portraits. Men in naval uniforms, beautiful women smiling up at them, young men standing proud on the decks of warships, girls perched on rocks. I moved closer to examine the pictures in more detail. Hold on. Were they girls, or were they —

  What was that?

  A bell clanged loudly, echoing down the corridor.

  I glanced furtively around. Was it me? Had I tripped an alarm? Was someone going to come out and catch me? No! Please don’t let me be captured again! Memories of being caught and imprisoned in an underwater cell after I’d awoken the kraken rushed through me with a horrible shudder. I couldn’t get caught here!

  There was a recess behind me, a heavy wooden door at the back of it. I jammed myself into it, my heart almost bursting out of my mouth. Pinning my body to the door, I held my breath, shut my eyes tight, and prayed for the alarm to stop.

  And then it did. Stopped dead. Silence all along the long corridor. Nothing moved.

  My body sagged in relief as I leaned against the door, letting out a long breath and trying to decide what to do next.

  The relief didn’t last long. A moment later, I heard footsteps. They were coming from behind the door, getting closer! There was no time to hide. My body froze as I stood in the recess.

  And then the door opened.

  I was looking into a pair of very green and very surprised eyes.

  “Who are you?” asked the boy, staring back at me. He was tall, taller than me anyway, and skinny like me too. He was probably about the same age, maybe a little older, and dressed in black flared trousers and a black T-shirt. He had long jet-black hair parted perfectly in the middle and the most piercing green eyes I’d ever seen, which he continued to fix on me.

  For a brief second, I remembered Millie’s prediction about a tall, skinny stranger. Was this him? What had she said about him? I couldn’t remember. I tended not to listen carefully to Millie’s fortune-telling. For once, I wished I had.

  “I — I —” was all I managed to say.

  The boy glanced quickly down the corridor before beckoning me into the room. “You’d better come in,” he said, recovering more quickly than me. His voice was silky and smooth, like his hair, and serious, like his face.

  As I followed him into the room, I forced myself to speak. “I’m Emily,” I said. I couldn’t think of anything else to say. I looked awkwardly around me. Three of the walls were covered with maps and scrolls. There wasn’t a blank inch. Every country and every ocean in the world must have been on these walls. The fourth wall had a long rectangular window that looked out to sea. Beneath it, a thick wooden bookcase held rows and rows of books, brown and bound in gold like the ones in the library. The room felt almost unreal, as though the books and maps were part of a stage set and underneath them lay a thousand years of history and mystery.

  The boy noticed me looking. “They’re from my ancestors,” he explained.

  “Your ancestors?”

  “Pirates, captains, travelers of all kinds,” he said. “Many ships have been wrecked on the rocks of Half Light Castle.”

  I nodded as though I understood.

  “Look, sit down,” he said, gesturing to a huge armchair. With its thick, dark wooden arms and green velvet seat, it reminded me of the furniture in the stately homes I’d seen in some of Mom’s books. Mom. Just the thought of her made me ache. Where was she now? Was she trying to find me? Would I ever see her again? Each question was like a knife twisting around and around in my chest.

  The boy went on staring at me as I sat down. He pulled up an identical chair and sat opposite me. “I’m Aaron,” he said. He held out a skinny arm to shake my hand but almost instantly changed his mind and pulled it away.

  We fell silent. I didn’t have the first idea what to say. Well, come on. How many times do you think about what you’d do if you swam to a spooky castle floating on a mist in the middle of the ocean and accidentally landed in some strange boy’s room?

  Exactly.

  He was the first to pull himself out of the shocked silence. In fact, now that I thought about it, he was more mysterious and cool than shocked. Perhaps he was used to strange things happening. Or perhaps he was just a mysterious and cool kind of boy. Either way, I was intrigued — and thrown off balance — by him as much as by everything else that had happened in the last couple of days.

  “How did you get here?” he asked.

  “Um, I swam,” I said uncertainly.

  His eyes opened even wider. “You swam?”

  I nodded. “Through tunnels. But where am I? What kind of a place is this?”

  “Half Light Castle. It’s my home,” said Aaron. “I don’t know any other.”

  “You’ve lived here all your life?”

  He nodded. “All my life. Here and nowhere else, like every generation before me, all the way back to . . .” He looked up at me through his thick black eyelashes. “No, I can’t tell you that.”

  “Can’t tell me wh
at?”

  “My family history,” he replied with a grimace. “It’s not exactly straightforward. You’ll never believe me.”

  I laughed. “You think your family history is hard to believe. Wait till you hear mine!”

  He didn’t smile. “Trust me. It’s complicated. Or it was. There’s nothing too complicated now, though, as it’s just Mother and me.”

  “Just the two of you in this whole place?”

  “And a few si —” He stopped himself, covering whatever he was about to say with a cough.

  “A few what?” I asked.

  “Servants,” he said quickly.

  “You weren’t going to say that. What were you going to say?” I insisted.

  Aaron shook his head and stood up. “I don’t think I can tell you,” he said. “I’m not sure. Look, why don’t you tell me about you instead? How did you get here? It’s supposed to be impossible.”

  “It nearly was,” I said. “I tried again and again.” Could I tell him about the ring? It was tight on my finger, the diamond warm against my closed palm. I could feel it almost scorching my hand, getting hotter. What was it saying? Tell him? Or keep it to myself?

  Why should I keep it secret, anyway? I had nothing to hide. “Look, if I tell you, you promise you’ll believe me?” I wanted to tell him. I felt I could trust him. I don’t know why. There was just something about him that I could connect with. As though we spoke the same language.

  “Why would I do otherwise? Why would you lie?”

  “OK,” I said. “Well, it was this. It kind of led me here.” I held my hand out and opened my palm to reveal the ring. “Now, I know you’ll think I’m making it up or you’ll think I’m crazy or something, but I promise I’m telling you the —”

  “Where did you get that?” Aaron reached out and grabbed my hand, pulling it toward him to look closer. His voice shook so much I could barely understand what he’d said. He swallowed hard, catching his breath. His pale face had turned even paler. “Where did you get it?” he repeated.