He appeared to wrestle obscurely with his feelings. ‘I’m sorry about that,’ he said at last, ‘inexcusable outburst. I’ve been busy lately and worried, and there you are. The Ancreds, collectively, have tried me rather high. Why, may one ask, do they suspect arsenical poisoning?’

‘It’s a long story,’ said Alleyn carefully, ‘and it involves a tin of rat poison. May I add also, very unprofessionally, that I shall be enormously glad if you can tell me that the condition of the room and the body precludes the smallest likelihood of arsenical poisoning?’

‘I can’t tell you anything of the sort. Why? (a) Because the room had been cleaned up when I got there. And (b) because the evidence as described to me, and the appearance of the body were entirely consistent with a severe gastric attack, and therefore not inconsistent with arsenical poisoning.’

‘Damn!’ Alleyn grunted. ‘I thought it’d be like that.’

‘How the hell could the old fool have got at any rat poison? Will you tell me that?’ He jabbed his finger at Alleyn.

‘They don’t think,’ Alleyn explained, ‘that he got at it. They think it was introduced to him.’

The well-kept hand closed so strongly that the knuckles whitened. For a moment he held it clenched, and then, as if to cancel this gesture, opened the palm and examined his fingernails.

‘That,’ he said, ‘is implicit in the letter, of course. Even that I can believe of the Ancreds. Who is supposed to have murdered Sir Henry? Am I, by any pleasant chance?’

‘Not that I know,’ said Alleyn comfortably. Fox cleared his throat and added primly: ‘What an idea!’

‘Are they going to press for an exhumation? Or are you?’

‘Not without more reason than we’ve got at the moment,’ Alleyn said. ‘You didn’t hold a post-mortem?’

‘One doesn’t hold a PM on a patient who was liable to go off in precisely this fashion at any moment.’

‘True enough. Dr Withers, may I make our position quite clear? We’ve had a queer set of circumstances placed before us and we’ve got to take stock of them. Contrary to popular belief, the police do not, in such cases, burn to get a pile of evidence that points unavoidably to exhumation. If the whole thing turns out to be so much nonsense they are, as a general rule, delighted to write it off. Give us a sound argument against arsenical poisoning and we’ll be extremely grateful to you.’

Dr Withers waved his hands. ‘I can’t give you, at a moment’s notice, absolute proof that he didn’t get arsenic. You couldn’t do it for ninety-nine deaths out of a hundred, when there was gastric trouble with vomiting and purging and no analysis was taken of anything. As a matter of fact—’

‘Yes?’ Alleyn prompted as he paused.