‘To your knowledge had he any enemies? That sounds melodramatic, but had he? Or, to put it another way, do you know of anyone to whom he might have done any damage if he had lived?’

There was a long pause. From the lane came the sound of a car in low gear. Alleyn could see through the window that a canvas screen had been erected. His colleagues, evidently, had arrived.

‘I’m just trying to think,’ said Mr Period. He turned sheet-white. ‘Not in the sense you mean. No. Unless – but, no.’

‘Unless?’

‘You see, Alleyn, one does follow you. One does realize the implication.’

‘Naturally,’ Alleyn said. ‘It’s perfectly obvious, I’m sure. If a trap was laid for Mr Cartell last night, I should like to know if there’s anyone who might have had some motive in laying it.’

‘A booby-trap, for instance?’ He stared at Alleyn, his rather prominent front teeth closed over his underlip. ‘Of course I don’t know what you’ve found. I – I – had to go out there and – and identify him, but frankly, it distressed me very much and I didn’t notice – But, had, for instance, the planks over the ditch – had they been interfered with?’

‘Yes,’ said Alleyn.

‘Oh, my God! I see. Well, then; might it not all have been meant for a joke? A very silly, dangerous one, but still no more than a booby-trap? Um? Some of those young people in the treasure hunt. Yes!’ Mr Period ejaculated. ‘Now, isn’t that a possibility? Someone had moved the planks and poor Harold fell, you know, and perhaps he knocked himself out and then, while he was lying unconscious, may not a couple – they hunted in couples – have come along and – inadvertently dislodged the drain-pipe?’

‘You try dislodging one of those pipes,’ Alleyn said dryly. ‘It could scarcely be done inadvertently, I think.’

‘Then – then: even done deliberately out of sheer exuberance and not knowing he was there. A prank! One of those silly pranks. They were a high-spirited lot.’

‘I wonder if you can give me their names?’

As most of them had come from the county, Mr Period was able to do this. He got up to twenty-four, said he thought that was all, and then boggled.

‘Was there somebody else?’

‘In point of fact – yes. By a piece of what I can only describe, I’m afraid, as sheer effrontery, the wretched Leiss and that tiresome gel, Mary Ralston, got themselves asked. Desirée is quite hopelessly good-natured. Now he,’ Mr Period said quickly, ‘in my opinion would certainly be capable of going too far – capable de tout. But I shouldn’t say that. No. All the same, Alleyn, an accident resulting from some piece of comparatively innocent horse-play would not be as appalling as – as –’

‘As murder?’

Mr Period flung up his hands. ‘Alas!’ he said. ‘Yes. Of course, I’ve no real knowledge of how you go to work, but you’ve examined the ground no doubt. One reads of such astonishing deductions. Perhaps I shouldn’t ask.’