‘Rigor mortis,’ said Alleyn, ‘has disappeared. The body is flaccid. But notice the difference between the right hand and the left. The fingers of the right are still curved slightly. If I flash this light on the under-surface of the table, you can see the prints left by the fingers when they clutched it. Bailey had brought them up with powder. You took a shot of these, Thompson, didn’t you? Good. As rigor wore off, you see, the fingers slackened. Now look at the left hand. It is completely relaxed and the fingers are straight. On the undersurface of the table-edge, about three inches to the right of the left hand, are four marks made by the fingers. They are blurred, but the impression was originally a strong one, made with considerably pressure. Notice that the blurs do not seem to have been caused by any relaxation of the fingers. It looks rather as if the pressure had not been relaxed at all, but the fingers dragged up the edge while they still clutched it. Notice that the present position of the hand bears no sort of relation to the points—it is three inches away from them. Did you find any left-hand prints on the top of the table, Bailey?’

‘No, sir.’

‘No. Now, taking into consideration the nature and direction of the blurs and all the rest of it, in my opinion there is a strong assumption that this hand was forcibly dragged from the edge of the table, possibly while in a condition of cadaveric spasm. At all events, there is nothing here to contradict such an assumption. Now have a look at this cup. It contains dregs of what we believe to be nitric acid and is standing in a stain made, presumably, by nitric acid. It is on the extreme right hand of the body. You’ve tried it for prints, Thompson, and found—?’

‘Four left-hand fingerprints and the thumb.’

‘Yes, by Jove!’ Alleyn bent over the cup. ‘There’s a good impression of the left hand. Now see here. You notice these marks across the table. It was thickly covered in dust when this man sat down at it. Dust on the under-surface of his sleeves—lots of it. If we measure these areas where the dust has been removed and compare it with the length of the sleeve, we find pretty good evidence that he must have swept his arms across the surface of the table. Something like this.’