‘I think you need to speak to the Captain.’

Franklin met Parsons in the corridor. They’d moved the patient out of the sickbay, into one of the empty staterooms reserved for scientists.

‘How’s he doing, Doc?’

‘Stable, sir. Temperature’s back up to ninety-eight, fluids good. As long as he keeps warm, he’ll be fine. He’s a survivor.’

‘Yes he is.’ Franklin reached for the door handle, but didn’t open it. ‘Is there something else, Lieutenant?’

‘His psychological condition, sir. I’m not qualified to assess it, but he seems pretty locked down. Experiences like what he’s had, sir, it’s got to screw with your mind.’

‘No argument with that.’

‘Chief Bondurant has CISM training, sir.’ Critical Incident Stress Management. ‘I could ask him to speak to the patient.’

Franklin turned the handle. ‘When I’m done.’

Anderson lay on the bed under a small mountain of pink blankets. They’d dried him off and dressed him in regulation-issue pants and sweater; Franklin was surprised they’d found any big enough. He sat propped up on a couple of pillows, eyes open, staring unblinking at the mirror over the washstand opposite.

Franklin rapped on the open door. The gaze switched on to him like a light coming on.

As captain, he was used to commanding nearly a hundred men for months at a time, in some of the toughest waters on the planet. He didn’t get many situations that made him feel uncomfortable on his own ship. But the intensity of those dark eyes, clear as a child’s, was hard to take. As if the ice had distilled them down to their coldest core.

He pulled a chair from under the desk and set it next to the bed. He looked over the report that Santiago had typed up.

‘How’re you doing?’

‘Fine.’ A soft voice, hard to match with the physique. Almost shy.

‘Your name’s Thomas Anderson.’

‘Yes.’

‘Are you a US citizen?’

‘English.’

‘You’re a long way from home.’

‘We’re both a long way from anywhere.’

Franklin accepted that. ‘You want to tell me how you got here?’

‘I was a research assistant. At Zodiac Station. It’s a scientific base on the island of Utgard.’

‘I know where it is. What happened?’

‘An explosion. I don’t know why. I was out checking instruments — there was nothing I could do.’

‘When was that?’

‘What day is it today?’

‘Wednesday, ninth April.’

‘It happened on Saturday. Four days ago.’

‘You skied a hundred miles over the ice in four days? By yourself?’

‘I came to get help.’

Franklin looked at Santiago’s report again. ‘You stated to the operations officer that all other Zodiac Station personnel are dead.’

Anderson’s eyes locked on Franklin’s — and, again, Franklin found he had to look away. He glanced out the porthole, but there were no answers in the grey world out there.

‘You’re British. You want a cup of tea?’

Anderson’s face thawed into a smile. ‘Love one.’

Franklin went out into the corridor. Santiago was waiting for him.

‘We can’t raise Zodiac Station, sir. Iridium, UHF, they’re not answering.’

‘Who owns that place? Did you try them?’

‘The Brits run it out of some place called Norwich. As in Connecticut, but in England. We put in a call — they haven’t heard from Zodiac since Saturday. They said Zodiac reported comms problems a few days ago and were taking their satellite link offline for maintenance.’

‘Page the XO. Rig the flight deck, and get the helo out to Zodiac ASAP to take a look around.’

Santiago hesitated. ‘That’s right on the edge of its range.’

‘I know how far it is.’

‘Yes, sir.’

‘It doesn’t add up. This guy Anderson skis out of the middle of nowhere with nothing but the clothes he’s wearing. He says he’s been out there four days, nearly died, but did you notice his beard?’

‘Can’t say I did.’

‘Doesn’t have one. You think he found a bucket of hot water to shave out there?’

‘Maybe he wanted to leave a good-looking corpse.’

‘Then there’s this explosion at Zodiac. We need to get eyes on the ground.’

‘Yes, sir.’

Santiago headed for the wheelhouse. Franklin went to the galley and fetched a cup of tea and a mug of black coffee. Back in the cabin, Anderson was sitting up in bed, exactly where Franklin had left him, eyes fixed on the door like a dog waiting for its owner.

Franklin switched his pager to vibrate and sat down in the chair.

‘Why don’t you start from the beginning.’

For as long as I can remember, I’ve dreamed of the north. I suppose a lot of people do. That feeling you get with the first snowfall of winter, something like a cross between Christmas morning and the start of the holidays. The world’s new, the rules are suspended.

I was always a solitary child. Back then, those white deserts at the top of the globe fired my sense of adventure. I read Willard Price, Jack London, Alistair MacLean. Other boys could reel off every player who ever scored for Liverpool; I could tell you about Peary and Cook, Nansen and Amundsen. I grew up, a lot of things changed but my dreams didn’t. If anything, they were more urgent. The Arctic wasn’t a place to prove myself, but to lose myself. Somewhere to escape to.

You know what the two most seductive words in the English language are, Captain? New beginning. The north’s a blank page, tabula rasa, white space on our own private maps we can fill in all over again. Snow gives us hope that the world can be different. A glimpse of perfection.

I’d applied for a post at Zodiac twice before, but I didn’t make it past the selection boards. I thought I’d missed my chance. I was working as a technician in the Sanger lab at Cambridge — not high-status work, but I was glad to have it. I have an eight-year-old son, Luke; my wife died and I look after him alone. Between him and the job I kept busy enough. But every time it snowed, I felt that familiar tug, my internal compass swinging north again.

Then I got the email from Martin Hagger. You’ve heard of him? Ask some of your scientists — the biologists. He’s a big gun. Everyone thinks life began in the so-called primordial soup, a warm broth slopping around the tropics. Hagger’s theory was that it actually evolved at the poles: that the freezing and melting of the sea ice every year acted like a giant chemistry set to turbocharge the evolution of DNA. He found some pretty convincing evidence, made the papers and everything.

I’d studied with Hagger for my master’s, and the first year of my doctorate, before we parted ways. Since then, I’d kept up with his research, but we hadn’t spoken in eight years. Then, one day, there it was: an email from Hagger, inviting me to come to Zodiac as his research assistant. His previous assistant had had a wisdom tooth go wrong and needed to be evacuated. His loss, my gain. I had no idea why he’d chosen me of all people, after all that time, but I didn’t care. There aren’t many thirty-year-old lab technicians with a PhD. This was my shot. Tabula rasa.

The bureaucrats who run Zodiac fought it — hated it — but Hagger forced it through. No boards, no assessment. Forty-eight hours later, I was at Heathrow.

My sister was late. Ironically, it had snowed — only a centimetre, but the roads had jammed solid. Who expects snow at the end of March? Luke and I waited in the departure hall at Terminal 3, probably the most depressing place on earth, while the crowds tramped slush through the doors and the tannoy ran non-stop with delays and cancellations. Fog steamed off the passengers; the whole place stank of damp.

Just when I thought I might miss my flight, Lorna staggered in. There wasn’t much time for goodbyes. I gave Luke a long, tight hug and we both tried not to cry. When I let go, he gave me the envelope he’d been clutching. I smiled when I saw the address.