“It’s got to be Polaris,” says Conor.

  “What’s that?”

  “A nuclear submarine. I’ve seen programmes about them. They travel under the polar ice cap. It’s like a ship, Faro, only it sails underwater instead of on the surface.”

  “You mean that there are humans inside that metal thing?” demands Faro.

  “Yes. And enough missiles to vaporise half of Ingo,” says Conor grimly. We all stare at the submarine in silence, trying to absorb what its presence means. “It’s a thousand times more deadly than any shark, Faro,” adds Conor.

  Faro’s nostrils flare with revulsion. “Only humans would bring such a creature into Ingo,” he says.

  I was wrong when I thought the submarine had stopped moving. It’s coming closer. If there were windows on a submarine and the people in it could look out with binoculars, we’d be within range …

  Radar. How sensitive is the radar on a nuclear submarine? They must have all kinds of other tracking devices too. Maybe they are tracking us already. Someone might have just picked up our images on a computer screen. We’ll show up as four living, pulsing dots. Maybe their technology is so advanced that they’ll even be able to hear our heartbeats. What if they were able to pick out our arms and legs – or our tails …

  Take a look. You ever seen anything like this before?

  Increase the image magnification immediately. Alert the bridge.

  “Conor! What if they can see us on radar, or pick up our body heat or something?”

  Conor’s eyes widen. He turns quickly to Faro and Elvira. “It could be able to hear us and see us, the same way a whale can. The submarine has all kinds of equipment inside it. We’ve got to get away before it spots us.”

  Faro turns aside and spits in disgust, just as he spat when he told me about Mortarow’s spear.

  “Faro!” exclaims Elvira, sounding horrified, but Faro ignores her. Instead, he seizes my right hand and pulls me forward towards the current. The submarine swings slowly, probing the water. What if the people on board suspect we’re enemies?

  “This time, keep close to us!” Faro shouts over his shoulder to Conor. One by one, we manoeuvre ourselves into position. We’re beside the current now. I feel the force of it tingling on my skin, although it’s not even touching me. A first faint nudge comes through the water, and then another, stronger. Suddenly I’m not afraid. My blood races, like the current. The suction seizes hold of my right hand, and I am gone.

  We speed through the dark, beneath the ice. I don’t know how long we’ve been in the current. Ingo time ebbs and flows so strangely that I’ve almost given up trying to understand it. Sometimes what I’m sure is only a minute turns out to be an hour. I’m sure we’ve travelled a long way. Hundreds of miles, maybe thousands. I know that Faro is close, because I can hear his thoughts beaming out towards me.

  I am here, little sister.

  Sometimes I feel a wave of Faro’s exultation. He is loving this current, riding it like a surfer riding the biggest wave in the world. I know how he feels because the same exhilaration courses through me. Behind Faro’s thoughts I can pick up the shadow of Elvira’s. She’s in touch with Conor somehow. She assures us that he’s safe.

  I can’t feel any bubbles against my skin. The current seems to have crushed everything into a river of speed. It’s not jade green any more, but black, because there is no light at all. I know that we are under the ice because we glimpsed it above us, before the dark swept over us.

  I keep thinking about Dad. Not Dad as he is now, but Dad as he was a few years ago when he kept getting such terrible headaches that our doctor sent him upcountry for an MRI scan on his head. Dad said when he was in the scanner it sounded like a huge hammer being hit very fast, over and over, inside his brain. The current is like that. I thought it would be a smooth rushing sound but it’s a thundering noise, as if all the atoms in the water are flying apart and then being smashed together again at high speed. I wonder where the current is taking us, and how long we’ve got to travel like this? I can’t see anything; I can’t taste or smell anything. All I know is the roar of the current, and the pulse of elation inside me.

  I think I’ve been asleep.

  Are you there, little sister? Faro sounds worried.

  Wearily, I put out a tendril of thought. I’m OK. What about you?

  I’m fine. No exultation any more. Maybe he’s just tired, like me. I wonder how long I’ve been asleep. I reach out for Elvira, and sense her presence close by, but not what she’s thinking. She’s relaxed, peaceful. Conor must be with her.

  Conor? Elvira, is Conor there?

  We’re fine, Sapphire. Don’t worry about us, Elvira replies.

  It’s obvious that Elvira doesn’t suspect that there’s any problem between Conor and her. The word “we” is so proud and happy in her thoughts that I feel a bit embarrassed … and a little bit ashamed. Quickly, I hide my thoughts from Elvira. But just as I break contact, the steady roar of the current breaks up into sudden chaos. There’s a confusion of giant waves charging together, surging, crashing, smashing on my ear drums until I cry out with pain. Just when I think I can’t bear it any longer and my head will burst, the noise disappears. Silence sweeps in. My ears are still ringing with the bludgeoning of the waves, and for a moment I wonder if I’ve gone deaf.

  Conor? Faro?

  I’m here. It’s Faro’s voice.

  Are we still moving, Faro?

  I think so.

  The thunder returns, but it’s distant now. It’s up ahead, and although we’re not in it we are moving towards it. It reminds me of something that I know from the human world. My blood prickles uneasily in my veins as I reach for the memory.

  A waterfall. That’s what the distant roar sounds like.

  “Faro!” I shout as a thrill of terror races through me.

  At that instant the current jackknifes. I am thrown forward, then back, then I’m tossed upside down by raging water. The current convulses as if its back has been broken. The next moment it’s hurtling forward again as the thunder swells. I reach out desperately for Faro with my mind. We can’t be separated now. Faro! Where are you? I stretch every fibre of my thoughts, searching.

  Faro’s there, trying to get through, his thoughts reaching out for me. I haven’t lost him. Sapphire!

  Where are the others?

  A pause. Faro’s mind will be sweeping the wide dark current, trying to pick up a sign of his sister.

  She is there, he tells me at last. The flood of relief in his mind pours through me too. “They are just behind us. The deublek on Faro’s wrist brushes mine, and I grab his hand and hold on tight. I don’t want to lose anyone ever again.

  I’m not prepared for Faro’s blaze of elation. I don’t understand. What’s happened? What is so wonderful?

  “South, Sapphire! We’re heading south!” He is wild with excitement. I still don’t understand. We don’t want to go south. The southern route is blocked by the sharks and by Ervys. We’ve come all this way and risked the northern route because it’s our only chance of outwitting them.

  “Come back, little sister.”

  It’s Faro. He is speaking right into my ear. “If we were not in this current, I would turn a hundred somersaults for you, Sapphire, and then you would smile.”

  “I don’t see that there’s anything to smile about if we’re going south.”

  “Don’t you understand?”

  “There’s nothing to understand. We need to go north, and we’re going south. We’ve failed.”

  He is laughing. He is actually laughing.

  “You humans! I think you believe that the world is like a flat rock, and when you come to the edge of it, you fall off. No. We have gone as far north as it is possible to travel, little sister, and because the world is round we must go south again. I have heard of it before, but never thought I would feel it through my own body. You must have felt the current turn. Did you not feel the North spin away from you?”

  I
hardly dare to believe him. It sounds too good to be true.

  “But I don’t know which way is north, Faro.”

  “Of course you do,” says Faro impatiently. “That’s the one thing everyone always knows.” He makes it sound as obvious as hearing your own heartbeat.

  “I think that knowing where north is might be ‘a Mer thing’,” I say, quoting his most annoying expression. “We could be going east or west for all I know.”

  “But how do you ever travel without knowing where north is?”

  “We use maps, and compasses and sat-nav. You know about maps. You’re always saying they’re rubbish.”

  “You will have to tear up all your human maps which make the world as flat as a rock, because they are wrong,” says Farogleefully. I don’t bother to argue. It’s not worth resisting Faro when he’s in this mood of glittering excitement. I almost believe I’ll see the flash of his eyes through the enveloping gloom. “You’re not going to fall over any cliff. Hold on, little sister. We are heading for the bottom of the world.”

  South. South. As we travel on I keep testing the word. Maybe the current carried us all the way to the North Pole, beneath the polar ice sheet. Now we’re rushing southward, still in the darkness, still beneath a thick sheet of ice.

  The Antarctic is land surrounded by ocean. The Arctic is ocean surrounded by land.

  We’ll have to find a different passage south through the land mass that hems in the Arctic Ocean.

  Dad’s globe swims into my mind. In my imagination I make it spin, as I’ve done so often. The strange thing is that although I’m on the longest journey through Ingo that I’ve ever made, it’s easier to think of Air and the human world than it’s ever been before. It feels as if they are connecting somehow, inside me, rather than fighting each other as they have always done. It doesn’t feel dangerous to make the globe turn. Maybe this is what Saldowr meant by peace. Peace inside me, between Mer and human. Peace outside, between Ingo and the human world, because the two of them can connect at last …

  I remember now. There is a passage. It’s a narrow strip of sea between the far west of the United States – Alaska – and Siberia. Two huge continents almost meet there, but not quite. That’s the passage we’ll have to find. I can’t begin to imagine how we’re going to do that.

  I’m not afraid. I’ll think about that problem when I have to. For now it’s enough to be travelling, close to the others even though I can’t see them. It’s enough to be lulled by the hypnotic drumming of the current, and to be carried onward, onward, wherever it chooses to go.

  I sleep for a long, long time. When I struggle up again through layers of dreams, it feels as if I’ve been unconscious for days rather than hours. I was dreaming about Dad, and about my baby half-brother Mordowrgi. In my dream he was swimming with us, and we kept telling him that he was much too young to make the Crossing of Ingo, but he only laughed and swam faster inside the circle of my arms.

  I push the veils of dream away and open my eyes. At first I’m not surprised to find that it’s light. A very faint, ghostly grey light, but light. Then I remember the blackness in which I fell asleep, and the thick crust of ice between us and the surface. I look up, and all I can see is water. I turn sideways, and there is Faro, within touch, smiling at me quizzically.

  “So you’ve come back to us, little sister,” he says. And there are the others, Elvira still drowsing with her long hair wrapped around her like a cloak, Conor wide awake.

  “It’s amazing to see you again, Saph, after all that time in the dark,” he says. The current isn’t too loud now; we can hear each other speak. “I kept telling myself you were safe, and I knew you had to be because Elvira said so. But it’s so different when you can see someone with your own eyes.”

  “You look different, Conor.”

  “How do you mean?”

  “I don’t know … Yes, I do! You look older.”

  “So do you, little sister,” observes Faro.

  Maybe we’ve all been asleep for years, like in that fairy story where two children fall asleep on a mountain and then return to their home villages and find all their friends are old and grey with long silver beards. I examine Conor’s face more carefully. It’s his expression that makes him look older, not lines or anything like that. I wonder if Faro’s right, and I’ve changed too.

  “Wow – we’ll be able to say we’ve been to the North Pole,” I tell Conor.

  I visualise Dad’s globe again, and am glad I used to study it so carefully. Geography can be useful; more useful than Faro realises, I think rather smugly. “We need to find the passage between America and Siberia,” I tell them.

  “America. Siberia,” repeats Faro sarcastically. “But we are making the Crossing of Ingo, not ripping the Air apart in one of your aeroplanes. What use are human names to us?”

  I’m about to snap back at him, but Conor angles his body against the thrust of the current and swims up beside me. “We’ll never find a fifty-mile-wide strait when there are thousands and thousands of miles of land south of us, Saph. We’d die trying. Faro says that a strong current like this will know its own way south. There’s nothing else to guide us. We’ve got to go with the current, and trust it.”

  Elvira is awake now. With both hands she pushes back her hair from her face. “Why is it light, Faro?” she asks sharply.

  “We are no longer under the ice.”

  “We must leave this current and find another. We’ve got to keep going north!” Elvira sounds scared, almost panicky. Her eyes are like wide black holes in her face. I can’t help feeling a pang of sympathy for the shock she feels, waking into a different world.

  “We have to go north!” Elvira swims to us, and grasps Conor by the arm, looking into his face. “Don’t you understand?”

  “It’s all right, Elvira,” he says soothingly, “we’re heading in the right direction. We had to go north to get to the top of the world, more or less, and now we go south.”

  “But—” Elvira breaks off, looking from one of us to the other. Her hand goes to her mouth. Her eyes are desperate. I remember my brother’s words about how Elvira seemed like a different person as she urged him north: She wouldn’t let me rest for a second. She kept pulling my arm and making us keep going north. And she’s strong, Saph …

  She doesn’t look strong now. She looks anguished, and I can’t help feeling sorry for her.

  “The North,” whispers Elvira, “I have to go there. That is my journey, don’t you understand?”

  Now Faro is beside his sister. “Elvira,” he murmurs, “I cannot make the Crossing without you. Stay with us.”

  Elvira puts out a hand, testing the strength of the current. Her tail lashes. Is she going to try to force herself out of the current? But it’s already carried us hundreds of miles south – maybe thousands. She’ll be alone, and lost. Easy prey for the first polar bear or orca that chooses to forget she is Mer. Or she’ll die of hunger and exhaustion.

  “No, Elvira! You mustn’t!”

  Elvira looks startled. Maybe she didn’t think I cared that much about her. “But, Sapphire,” she says, her voice tight with pain, “I belong there, in the North. I never knew it before. I can be happy there.”

  “You will be happy alone,” says Faro harshly.

  “No, not alone, I am sure of it. There are Mer in the northern waters, I have seen them.”

  “I haven’t seen any,” says Faro.

  Conor stares at Elvira. “We didn’t meet any Mer, Elvira.”

  “But—” Elvira starts speaking, then stops. I have a flash of insight. The Atka. Maybe Elvira has an Atka too. Maybe Elvira saw her Atka, listened to her, even touched her. Maybe Elvira really did meet those northern Mer with their silver hair and skins as pale as the moon, when Conor was sleeping. Something has happened to fill Elvira with such conviction that she belongs in the North.

  All this time, the current is sweeping us south. Elvira realises it, and gives a sudden, despairing cry. “Faro! What am I go
ing to do?”

  Faro puts an arm around his sister and her hair swirls, covering both their faces. They murmur together, privately. Conor and I swim away a few metres, not wanting to eavesdrop.

  “You could persuade her, Conor,” I whisper. Elvira would do anything for Conor … or at least, I thought she would …

  “Not about this,” says Conor. “Let Faro do the talking, Saph.”

  Faro and Elvira talk for a long time while the current bears us along at a speed so quiet and effortless that it hardly seems like speed at all. At last Faro swims across to us. “Elvira will complete the Crossing with us,” he says.

  Conor nods quickly, but his colour deepens and I know how relieved he is. He must have thought there was a real risk she’d leave us. Faro throws back his head in his old gesture of pride and resolve. How pale he looks, in spite of his dark skin. And how stressed.

  “I have promised her that when we return home, she will have her choice. If she still wishes to go to the North I will not stop her. I will help her.”

  He stares straight at us, daring us to comment or to pity him. The current is the only thing that moves; Conor and I are frozen. I want to say something or do something, but I know it won’t help. Elvira is Mer and the forces that are pulling her to the North are beyond my understanding. I remember the Atka gliding towards me on her ice floe and I shiver. The North wants Elvira and it’s powerful enough to take her from us.

  “But why now, Faro? Why has Elvira suddenly changed like this?”

  “The North has touched her, and Elvira’s spirit has answered it. Her fate lies there.”

  It will tear Faro apart to help his sister to leave him and everyone who knows and loves her, but he will do it all the same. Faro keeps his promises.

  I touch the deublek on my wrist and feel Faro’s eyes on me.

  “We two are joined together, little sister,” he says, as if we’re alone and Conor cannot hear us. “No one can separate us, until we choose to part.”

  CHAPTER SIXTEEN