I gave myself a threshold of ten minutes’ rat-watching time - any less and I’d be out cold again, any more and I’d be whistling down the seconds until her finger squeezed the trigger and it was all over. After seven and a half minutes the rat scuttled under a bed in the corner and started biting at a dirty piece of gauze, and I felt ready.

I leaned over and gently prised the gun from Akuji’s hands. It was a version of the Tokarev: unmarked, but possibly Chinese, by the look of the barrel lug. China was supporting the Biafrans, so that made some sense. I checked the pistol - fully loaded - and placed it in my waistband. Finally, my lesson from Pritchard from all those years ago in a clearing outside Frankfurt: pockets. They had nothing in them but the packet of Three Fives in his jacket, which I decided to take. I slid a cigarette out and lit it. The nicotine burned my lungs and brought some fire back into my head.

After I’d taken a few drags, I grabbed hold of the table Akuji had crashed into for leverage and pulled myself to my feet. Several bottles had been smashed and thick sharp-smelling liquids were flowing into each other across the metal tray. Taking care not to touch any of the broken glass or liquid, I examined the small bottles, turning the tops of them with my fingers so I could read the labels. Most had trade names I didn’t recognize, but one I did. In bold black letters was a word that might save me: Benzedrine.

The small type on the bottle said it was ‘fast-acting’: I timed it as seven minutes before the tablet started to take effect. In that time, I found a white coat on one of the beds and put it on, and I was in the middle of ripping a sheet into strips so I could tie Akuji’s hands together when the fatigue lifted and my senses came alive and I heard the footstep at the top of the stairs.

‘Is he dead?’ said the man in the mask as he surveyed the scene: Akuji on the ground and a half-crazed British spy shaking a pistol at him.

I took the cigarette from my mouth to answer, and promptly threw up all over my trouser-leg. There was blood in the vomit, and the man responded to his professional instincts and stepped forward. I waved the pistol at him and grunted threateningly, and he got the message and stopped, and I sorted out my throat and used some of Akuji’s uniform to wipe off the stuff and then looked back at him again through stinging eyes, took another drag and tried again: ‘He’s just out of action for a while,’ I said.

The doctor nodded. ‘Please get back into bed now,’ he said. I had to admire his sangfroid.