‘I – I hope not,’ he said hurriedly. ‘It’s all very unfortunate but never mind,’ and again he showed great uneasiness.

‘It’s infuriating to lose a good case,’ Alleyn remarked. ‘I did myself, not long ago. It was a rather special and very old one and I regret it.’

‘So is this,’ Mr Period said abruptly. ‘A card case.’ He seemed to be in two minds whether to go on and then decided against it.

Alleyn said: ‘When you saw Mr Cartell last evening was he his usual self? Nothing had happened to upset him at all?’

This question, also, produced a flurried reaction. ‘Upset? Well – it depends upon what one means by “upset”. He was certainly rather put out but it was nothing that could remotely be related –’ Mr Period fetched up short and appeared to summon all his resources. When he spoke again it was with very much more reserve and control. ‘You would not,’ he said, ‘ask me a question of that sort, I think, unless you felt that this dreadful affair was not to be resolved by – by a simple explanation.’

‘Oh,’ Alleyn said lightly, ‘we needn’t put it as high as that, you know. If he was at all agitated or absent-minded, he might not be as careful as usual when he negotiated the bridge over the ditch. The dog –’

‘Ah!’ Mr Period exclaimed. ‘The dog! Now, why on earth didn’t one think of the dog before! It is – she – I assure you, Alleyn, a most powerful and undisciplined dog. At the moment, I am given to understand, particularly so. May she not have taken one of those great plunging leaps of hers, possibly across the drain and, dragged him into it? May she not have done that?’

‘She seems, at least, to have taken a great, plunging leap.’

‘There! You see?’

‘She would also,’ Alleyn said, ‘have had to dislodge a walloping big drain-pipe and precipitate it into the ditch.’

Mr Period put his hands over his eyes. ‘It’s so horrible!’ he said faintly. ‘It’s so unspeakably horrible.’ And then, withdrawing his hands, ‘But may she not have done precisely that very thing?’

‘It’s not very likely, I’m afraid.’

Mr Period stared at him. ‘You don’t think it was an accident,’ he said. ‘Don’t bother to say anything. I can see you don’t.’

‘I’ll be very glad if I find reason to change my opinion.’

‘But why? Why not an accident? That dog, now: she is dangerous. I’ve told him so, over and over again.’

‘There are certain appearances: things that don’t quite tally. We must clear them up before we can come to any conclusion. There must, of course, be an inquest. And that is why,’ Alleyn said cheerfully, ‘I shall have to ask you any number of questions all of which will sound ridiculous and most of which, I dare say, will turn out to be just that and no more.’