I'd told him only what we would be doing, and how to prepare himself, what to collect, conceal, and bring with him tonight. I hadn't given him all the actual phases, details, minutiae: there'd been no point. He'd been told the essentials, and told to go over them in his mind day and night until mentally he was brief-perfect. I'd challenged him on some of them and he'd got them right every time, but there was this impatient tone that came out sometimes, and I'd learned it wasn't only his expression of fear. Marius had been running the Sakkas empire for three years, and had been used to a high order of respect and instant obedience from his aides and underlings, wasn't used to anyone but Sakkas himself dictating to him. I'd gone with this as best I could, deferring to him when possible; but it worried me that he might turn arrogant later, when I would need to be in total and absolute charge.

The snow was coming in flurries now and still thickening. That was all right, but if it increased to blizzard strength it could become deadly.

I checked Igor's watch at 11:50 in the faint light. I'd timed zero for 11:55, because the main floodlights would normally be switched off at midnight and I wanted the initial phase to trip in before that, to cause confusion.

'Marius,' I said, 'it's fifty yards from here, and we'll have to pick our way over the new snow. Don't worry too much about making a noise – it'll be quite well covered. Just get there as fast as you can.'

'Understood.' There was a tightness in his tone now, and that was good: I wanted the adrenalin to run.

I helped him shrug out of his heavy striped greatcoat, and he helped me with mine; then we buried them under the snow. Underneath we wore black bomber jackets, stolen at three o'clock last night from the reception hut where incoming prisoners were issued with new gear.

Another sound came in now: boots crunching from south of us, towards the centre of the camp.

'Flatten yourself against the wall,' I whispered to Marius, 'then freeze.'

I watched the shadow as it lengthened across the snow, a man's figure, the bulk of an assault rifle projecting from it. Rattle of a door handle as he tried the gym. The last two nights there'd been no sentries coming this far: I'd checked. Perhaps tonight it was the punctilious guard, the only one who tried the door handles.

If he comes any farther to check the rear end of the hut, strike to kill, don't risk anything now, it's too close to zero.

I could see the steam from his breath at the corner of the gym, lit from beyond him, then the sudden glint on the barrel of the rifle as he came into sight, his head turned in this direction, the beam of his torch swinging, the flurries of snow whirling between us, hiding me, revealing me. Hiding me enough? Revealing me too much? I couldn't turn my face away, needed to watch him, to prepare the strike.

To the other side of me there was nothing but the wall of the massif with its rocky outcrops, so perhaps I was blending in with it because the guard was still swinging his torch, over me and away again, the backglare from the snow half-blinding him as I stood with my eyes narrowed to slits, their lashes putting him surrealistically behind bars as I watched him.

If he keeps on coming we shall need great speed: go into the toraki-kuo within two seconds before he can bring up the gun.

To kill.

But he was turning now, the snow in his face, in his eyes, and his boots crunched away down the path from the gymnasium.

I checked my watch immediately: it was a minute to zero.

'He's gone?'

'What? Yes. Relax.'

I heard Marius let a breath out.

'We're beginning the count-down,' I told him, 'with less than a minute to go. You feeling okay?'

'Of course.'

Bloody arrogance.

Last one, Alex had said as he thrust the sacking bundle into my hands. The last one of six. He didn't know what I wanted them for, didn't know when I was going to use them.

Thirty seconds.

'Thirty seconds,' I told Marius. He didn't answer.

A flush of silver light was creeping across the snow from the east. It would be moonrise, but we couldn't watch it from here, from the west side of the gym.

The tin alarm clock had been less easy to get hold of. The prisoners hung on to any possession they could call their own; it made them feel like people of property. I'd had to trade my spare of issue boots for the clock.

Fifteen.

I told Marius, but again he didn't answer. What could he say, after all? Good luck? Of course we'd need good luck, every vestige of it that God Almighty could spare us, and you don't think I'm praying, do you? You think I never pray.

Ten.

Nine.

Eight.

The snowflakes whirled, pretty as cherry blossom as they blew past the corner of the hut.

Look, it was this or nothing, that's why I haven't gone mad.

The only choice was another forty years in penal servitude with Balalaika just a mention in the dusty record books, Mission abandoned, won't you get that into your bloody head?

Seven.

Six.

Five.

'Four seconds,' I told Marius.

We shifted our packs, settling the canvas straps.

Three.

I let my eyes rest on the snow where the light was brightening, and took joy from it, joy also from the cool kiss of the flakes as they landed on my upturned face and my eyelids as I closed them just one more time.

Two.

Opened them again to look across the camp under the tall floodlights.

One.

To look across at the shape of the huge diesel generator as the hand of the tin clock moved to zero and the sky was lit with a blinding flash and a moment later there came the shuddering whoof and the whole camp was blacked out and we began running for the wall of the thousand-foot massif.

I drove the piton into the seam and tested it with the rope but it pulled down at an angle and I drove it in harder, tested it, found it good and hauled up.

From three hundred feet the camp was lit with fireflies as emergency lamps came on. Flames still reddened the sky from the generator's diesel fuel, and black smoke rolled in waves between the huts.

Snow drifted past us from the east side of the massif, more heavily now, shrouding the moon, giving us a smoke screen on the face of the rock, which was miraculously free of too much ice.

'Haul up,' I called down to Marius, and felt the rope grow taut.

I'd got the half-Mongolian smithy in the forge to make me twelve pitons two days ago, adapting them from pit gear and grinding four of them into bird beaks in case we needed them. Of course we'd need them; we'd need a lot of other gear – hooks, friends, ice screws, pulleys, bolts, jumars – but all we'd got was what we could get, just the pitons, some crude carabiners, two broad-faced hammers, and two weighted picks made from rusty steel – the ones we used all day were impossible to take from the pits; they were counted whenever we knocked off. The rope had been easier to get away with from the stores, hemp, 12 mm, recently delivered, no fraying in it.

Andrei had made the pitons and the picks for me at the forge. He was massive, seven feet high, all muscle.

'From the city?' I'd asked him. His great oval face dripped with sweat.

'I am from the city, yes.'

'You've got people there? Relatives?'

'My mother.' He leaned on his five-foot hammer, watching me, his eyes crimson from the heat, an animal smell coming from his goat-hide apron.

'She okay?'

'She is okay. She is an old woman now. Why do you ask me?'

'I've been managing to get some mail through,' I said, 'to the city.'

'You must have friends.'

'Right. I need you to do a bit of metalwork for me, Andrei.'