‘Surprising, sir? I should just think so! You never know, sir, about anybody. Sir William was the last man, I should have said, to go about armed.’

‘But he wasn’t armed, sergeant,’ rejoined the doctor. ‘A man with a revolver is not armed unless he has something to fire out of it. That’s no more an arm than any other bit of old iron.’

The sergeant hesitated.

‘That’s so, sir, in a way, of course. Still—you can hardly think of anyone carrying an empty revolver. I expect he must have had the habit of carrying shells, but by some oversight forgot them yesterday.’

‘Possibly. There doesn’t seem to be much else of interest anyway.’

‘No, sir, that’s a fact.’ The sergeant, having emptied all the pockets, began laboriously to make a list of the articles he had found. Dr Ames had taken up a small diary or engagement book, and was rather aimlessly turning over the sodden leaves. Suddenly he gave an exclamation.

‘Look here, sergeant,’ he whispered. ‘Here’s what you have been wanting.’

There was a division in the book for each day of the year, with notes of engagements or other matters in most. At the bottom of the space for the previous day—the portion which would probably refer to the evening—was written the words: ‘Graham, 9.00 p.m.’

‘There it is,’ went on Dr Ames. ‘That’s where he was going last night. He evidently intended to consult Dr Graham privately. As it was too far to walk round by the road, and he didn’t want to get a car out, he thought he would take a short cut by rowing across the river.’

The sergeant made a gesture of satisfaction.