Free Hostage by Geoffrey Household

Shallope merely because I take on myself the responsibility for coldblooded murder. I can claim, like a hanging judge, that this is an unpleasant duty, but there is no family or club to which I can return for a glass of port and absolution.
    The Roke’s Tining bomb is Shallope’s own baby, not a standard production; so it will be fairly primitive – not amateur of course but of basic simplicity and made to fit into an outer container, the drain pipe, which we have specified. It must be as difficult to ensure the separation of the two charges of U235 as to drive them together. The foolproof, radiation proof tamping – what happens to that? Obviously it has to vanish instantaneously so that there is no risk of scattering the fissile material before it goes critical. That means that the explosive must be special stuff, producing a very high temperature and perhaps of little value as a propellant or for demolition.
    So I cannot see anybody but Shallope himself with the knowledge to place explosive and detonators precisely, wire up and prevent recoil. Meanwhile it must be possible without the slightest risk to crash down the drain pipe on a pile of others or force it into a disused sewer outlet. The final preparation therefore must be done on the final site, sliding the bomb out of its pipe, arming it and sliding it back again.
    No Shallope, no bomb. I think I can lay that down with certainty.
    There is an obvious alternative to killing him; but I cannot bring myself as yet to communicate, even anonymously, with the police and give them the facts so far as I know them. Illogical? Possibly. I could never face myself after such a betrayal. I must act alone. Sounds lovely, doesn’t it? But hypocrisy again! The truth is that if the police arrest Shallope, Clotilde and the few persons he can identify they will at once be forced to let them go and still will be without any clue to the present site of the bomb. As for me, I go back to gaol.
August 12th
    The day before yesterday Herbert Johnson made a business trip to Bristol, sold a few books in the morning and in the afternoon explored Clifton Down on foot. It turned out to be a square mile or more of open country, too clown-like and natural to be called a park, stretching between the Avon Gorge and the streets of Clifton and Bristol and on the far side falling away into farmland and suburbs. In places it vaguely reminded me of savannah country with trees and bushes of hawthorn sometimes isolated, sometimes in clumps, scattered over the grassland. Plenty of people were strolling about or playing games but the Down held them easily and I was sure that in the early morning not a tenth of them would be there.
    Provided that I could make some friendly contact with Shallope and provided the bushes gave sure cover for an instant the thing could be done. An instant was all I needed, for I intended to use the knife silently and decisively as I had been taught in Uruguay so that he would be dead when I lowered him to the ground.
    His flat was close to the Down. Next morning I watched him leave the house and got ahead of him once I was sure of his route. He walked briskly north over the grass, his hair ruffled by the damp wind which blew up from the muddy Avon far below at the bottom of its gorge. He was wearing a heavy yellow sweater which enabled me to keep him in sight whenever bushes intervened between us.
    When he had walked nearly a mile he turned and came back across the open where I had not a hope of attack, so I decided to meet him face to face. He would certainly recognise me, giving me a chance to enter into conversation and walk off with him into cover. It was, I must admit, an impatient, early-morning decision, for if anything went wrong he could describe me. But so he could anyway if I failed to kill him.
    He behaved oddly. When he was a few yards from me he turned away towards the gorge. A slight beckoning movement at the end of the swinging arm appeared to mean that I was to