Needs must.

Yea, verily, but 'tis easily said.

I stood with my feet close to the parapet, the toes of my calf-skin boots just touching it. This wouldn't be my point of departure: the parapet was ten inches high, twelve, a stumbling-block. My point of departure would have to be the top of the parapet, giving the legs leverage, the instep hooked over the front angle of the stone as I pitched forward, kicking out to send me past the point of no return, balanced in the air above the gap and for a moment flying, wingless, borne on hope alone – hope? You must be joking, we mean desperation, don't we, because there's no bloody choice and if we don't do this we'll go down under the tree, rat-tat-tat, and onto the forest floor.

Theice crackled, its sound infinitely slight as the ancient building moved under its own weight and the earth's rotation and the change in temperature as midnight pressed down on the mercury a degree at a time. The ice melted under my feet: I could feel it. The ice was everywhere, here where I stood, over there on the other side of the further parapet, treacherous, uninviting.

The night's chill pressed at the face, burned on the fingers still from the work of the grave-digging. Fear sat patiently at the threshold of the heart, awaiting admittance once the guard was down and the door swung back.

Rat-tat-tat and the rough barkof the tree grazing the neck as the body slumped, all we needed to give us the will to choose otherwise, so I scraped the frozen snow off the top of the parapet and stood with both feet on it and took in oxygen to fire the muscles and felt the rush of adrenalin and sighted across the gap and leaned into the skiing stance and waited until my weight carried me forward and felt the night close in to focus on this irrational act of sauve qui peut in the instant before I kicked out and thought of nothing more until the roof of the next building came slanting up and I flung my hands out to break the impact and brought my right shoulder into an aikido roll and followed it with another one and then a third as full consciousness came back after the gap in the mental process that had set in as I'd flown across the gap between the buildings, the high quarter-moon afloat in the void above me now, the sound of a car not far away in the street below, life becoming normal again, mundane.

'Jakub?'

I didn't move.

The voice was coming from the adjoining roof. 'Jakub, are you up here?'

Not in his entirety, no, just the chemical residue he left behind him under the makeshift tomb, don't go looking for him, don't start all that, the discovery and the sounding of the alarm and the hue and cry, for Christ's sake leave well alone, give me a break, don't stack these bloody odds, they're already as high as I can handle.

'Jakub?'

God's sake go away.

From where I lay I could just see the pale blur of his face as he left the doorway and looked around, swinging his Kalashnikov. I shut my eyes to hide the moon's reflected light in case he looked across here, would have liked very much to keep him in sight because I couldn't be presenting anything but the image of a man lying here on the melting snow, a man or a human body, perhaps Jakub's. But I had rolled into shadow, and this could give me a chance.

I lay in silence, listening for the movement of his boots, hearing the clink of the brass gun swivel as he turned, crunching over the frozen snow, the sound diminishing as it met the open doorway and ceased to echo.

Turning again. 'Jakub?'

To reassure himself before he clanged the iron door shut and I lay for another minute, waiting until the thudding underneath me between the rib-cage and the roof slowed to eighty, seventy-five, seventy and I rolled over and moved to the parapet where there should be a drainpipe, where there was indeed – look – a drainpipe, tilting down in perspective against the wall of the building, thinning to a point where the alleyway lay under virgin snow and for the moment unpatrolled, a haven, if you will, if I could get there, nine floors below.

The guard across there had taken a quick look for Jakub but he was still missing and at any given time there'd be someone else coming up to make a thorough search of the roof - Jakub? He was on the emergency staircase the last time I saw him, and as far as I know he hasn't come down – and they'd find the tomb and kick the snow aside and then it would start, the alarm and the hue and cry, so I'd have to reach the alleyway before it happened, reach ground and get clear.

So I kicked the snow off the top of the parapet and swung my legs over before rational thought could get in my way, rational thought and primitive instinct – I don't like this, you're going to kill yourself if -

Possibly.

It's nine storeys -

I'm glad you're learning to count at last.

It was solid, this drainpipe, square-section, cast iron, the way they made things in the nineteenth century, none of your thin tin tubing that wouldn't have given me a hope in hell, and between the pipe and the wall there was a gap an inch wide, not much but adequate for a finger hold. And below, halfway down with any luck, there would be creeper, thin tendrils at first and then larger, stronger, leafless and with the sap drained for the winter's hibernation but that made no difference; it would provide me with a rope, a life-line, so all is not lost, my good friend, providing the heart is sanguine and the will in charge.

And I was out of sight, had found cover.

Get Mr Croder.

Cover of a sort, the iron pipe freezing the fingers, numbing them as I let my weight drop another six inches and found new purchase with my feet.

The executive's found cover, sir.

Six inches in a hundred feet.

He can't have.

Because the last signal was still there, chalked on the board for the mission: Executive in red sector, no support requested.

Before I could relay any new signal through Ferris the red sector thing would have to be wiped out with the chalk-powdered block and they couldn't do that yet.

It's not terribly good cover, sir.

What the hell are you telling me?

It's a drainpipe, a hundred feet over a sheer drop.

And his hands, these hands, are frozen now, the bones providing claws and that was all: I could have done with Croder's steel grappling iron except that it would have made a noise, ringing through the hollows of the pipe, the sound transferred to the alleyway below.

For the first time I looked down, and saw no one, looked up again as the vertigo started like a worm in the cerebellum: a hundred feet, viewed from an angle of five degrees, looks like a thousand.

Let the weight go again, the toes of the calf-skin boots scraping the wall, the claws that used to be hands and fingers shifting downward another six inches, hooking into the gap again and holding as I waited, controlling the breath, I could use more adrenalin, more heat, but for that to happen there would need to be the onset of panic as the claws slipped and one boot lost its purchase and the other one followed and the dead weight, the dying weight of the shadow executive for Balalaika hung for a moment in the air and then dropped and gathered speed as the windstream played on the face and then tore at the cheekbones until the boots struck ground and the legs buckled, snapping at the knee joints, and by first light of the morning the director in the field would send the initial signal of the day: No further report from the executive, red sector call uncancelled. Request instructions.

Croder, wakened from a moment of snatched sleep at two in the afternoon – If he's still alive, pull him out and shut down the mission.