If I'd taken that impact I'd have broken my back or slipped enough discs to keep an orthopaedic surgeon in steady employment for months. But no shouts of agony from this lad. No gasps, even. Not a whisper of sound. Maybe he was a deaf mute — I'd heard of several deaf mutes possessed of this phenomenal strength, part of nature's compensatory process, I suppose.

But he'd been forced to break his grip, to grab swiftly at the tipper chain to save us both from toppling over the side into the cold dark waters of Loch Houron. I thrust myself away and spun round to face him, my back against the radio office bulkhead. I needed that bulkhead, too — any support while my swimming head cleared and a semblance of life came back into my numbed right leg.

I could see him now as he straightened up from the guard-rail. Not clearly — it was too dark for that — but I could see the white blur of face and hands and the general outline of his body.

I'd expected some towering giant of a man, but he was no giant — unless my eyes weren't focusing properly, which was likely enough. From what I could see in the gloom he seemed a compact and well enough made figure, but that was all. He wasn't even as big as I was. Not that that meant a thing — George Hackenschmidt was a mere five foot nine and a paltry fourteen stone when he used to throw the Terrible Turk through the air like a football and prance around the training ring with eight hundred pounds of cement strapped to his back just to keep him in trim. I had no compunction or false pride about running from a smaller man and as far as this character was concerned the farther and faster the better. But not yet. My right leg wasn't up to it. I reached my hand behind my neck and brought the knife down, holding it in front of me, the blade in the palm of my hand so that he couldn't see the sheen of steel in the faint starlight.

He came at me calmly and purposefully, like a man who knew exactly what he intended to do and was in no doubt at all as to the outcome of his intended action.