They walked in silence down the place, opened the door, and were joined by a very green Nigel. Alleyn filled his pipe and lit it. ‘To sum up,’ he said, ‘and for Heaven’s sake, all of you, check me if I go too far —we have difficulty in fitting the evidence of the hands, the table, the position of the body, the cup and the bottle, with any theory of suicide. On the other hand, we find nothing to contradict the suggestion that this man sat at this table, was given a dose of nitric acid, made a series of violent and convulsive movements, vomited, clutched the edge of the table and died. We find nothing to contradict the theory that his murderer dragged the left hand away from the ledge of the table and used it to print the bottle and the cup, and then left them on the table. I don’t for a moment suggest there is a good case for us here, but at least there is a better case for murder than for suicide.’ He looked from one dubious face to another.

‘I know it’s tricky,’ he said. ‘Curtis—how long would he take to die?’

‘Difficult to say. Fourteen hours. Might be more, might be less.’

‘Fourteen hours! Damn and blast! That blows the whole thing sky-high.’ ‘Wait a moment, Alleyn. Have we any idea how much of the stuff he took?’

‘The bottle was full. Miss Troy and Miss Bostock said it was full on Friday morning. Allowing for the amount that splashed over, it might have been quite a cupful.’

‘This is the most shocking affair,’ said little Curtis. ‘I—never in the whole course of my experience have I—however. My dear chap, if a stream of the stuff was poured into his mouth while his head was held back, he may have died in a few minutes of a particularly unspeakable form of asphixiation. Actually, we may find he got some of it down his larynx, in which case death would be essentially from obstruction to breathing and would take place very quickly unless relieved by tracheotomy. You notice that the portions of the face that are not dicoloured by acid are bluish. That bears out this theory. If you are right, I suppose that’s what we shall find. We’d better clear up here and get the body away. We’ll have the autopsy as soon as possible.’

It was almost dark when they got back to the Yard. Alleyn went straight to his room, followed by Fox and by a completely silent Nigel. Alleyn dropped into an armchair. Fox switched on the light.

‘You want a drink, sir,’ he said, with a look at Alleyn.

‘We all do. Bathgate, I don’t know what the hell you’re doing here, but if you are going to be ill, you can get out. We’ve had enough of that sort of thing.’