For a split second she looked irritated and then she said: ‘Not a bit. Do I gather that you want to go into a huddle with my husband?’

‘Just a word,’ Alleyn said equably, ‘if we may. Perhaps somewhere else –’

‘Not at all. I’ll go and snip the dead heads off roses except that there aren’t any roses and it’s the wrong time of the year.’

‘Perhaps you could get on with your embroidery,’ said Alleyn and had the satisfaction of seeing her blink.

‘Suppose,’ she suggested, ‘that you adjourn to Bimbo’s study. Why not?’

‘Why not?’ Bimbo echoed without cordiality.

As Alleyn passed her on his way out, she looked full in his face. It was impossible to interpret her expression, but he’d have taken a long bet that she was worried.

Bimbo’s study turned out to be the usual sporting-print job with inherited classics on the shelves, together with one or two paperbacks, looking like Long Acre in its more dubious reaches. Bimbo, whose manner was huffy and remote, said: ‘This is a very unpleasant sort of thing to happen.’

‘Yes, isn’t it?’

‘Anything we can do, of course.’

‘Thank you very much. There are one or two points,’ Alleyn said without refurbishing the stock phrases, ‘that I’d like to clear up. It’s simply a matter of elimination, as I’m sure you’ll understand.’

‘Naturally,’ said Bimbo.

‘Well, then. You’ll have heard that Mr Cartell’s body was found in a trench that has been dug in Green Lane, the lane that runs past Mr Period’s garden. Did you drive down Green Lane at any time last evening?’

‘Ah –’ Bimbo said. ‘Ah – let me think. Yes, I did. When going round the clues.’

He paused while Alleyn reflected that this was a fair enough description of his own preoccupation.

‘The clues for the treasure hunt?’ he said. ‘When?’

‘That’s right. Oh, I don’t know. About half past ten. Might be later. I simply drove over the territory to see how they were all getting on.’

‘Yes, I see … Was there anybody in the lane?’

‘Actually,’ Bimbo said casually, ‘I don’t remember. Or do I? No, there wasn’t.’

‘Did you get out of the car?’

‘Did I? I believe I did. Yes. I checked to make sure the last clue was still there.’

‘“If you don’t know what to do, think it over in the loo.”’

‘Quite. Was it still there this morning?’ Bimbo asked sharply.

‘When did you get back?’

‘Here? I don’t know exactly.’

‘Before Lady Bantling, for instance?’

‘Oh, yes. She drove old Period home. That was later. I mean, it was while I was out. I mean, we were both out, but I got home first.’

‘You saw her come in?’

‘I really don’t remember that I actually saw her. I heard her, I think. I was looking round the ballroom to see everything was all right.’

‘Any idea of the time?’