There was a fractional pause before she said: ‘Well, I must say P.P. has sharp ears for an elderly gent. Yes, I did. It meant nothing.’

‘And did you tell him to watch his step?’

‘Why,’ asked Desirée, ‘don’t we just let you tell me what I said and leave it at that?’

‘Did you tackle him about that boy of yours?’

‘All right,’ she said, ‘yes, I did!’ And then: ‘They didn’t tell you? Andy and the girl? Have you needled it out of them, you cunning fellow?’

‘I’m afraid,’ Alleyn prevaricated, ‘they were too far up the lane and much too concerned with each other to be reliable witnesses.’

‘So P.P. –’ She leant forward and touched him. ‘Look,’ she said, ‘I honestly don’t remember what I said to Hal. I’d had one or two little drinks and was a morsel high.’ She waited for a moment and then, with a sharpness that she hadn’t exhibited before, she said: ‘If it was a booby-trap, I hadn’t a chance to set it, had I? Not in full view of those two lovebirds.’

‘Who told you about the booby-trap?’

‘P.P. told Andy and Andy told me. And I drove straight here to Baynesholme arriving at twenty-five to twelve. The first couple got back soon afterwards. From then on I was under the closest imaginable observation. Isn’t that what one calls a water-tight alibi?’

‘I shall be glad,’ Alleyn said, ‘to have it confirmed. How do you know you got back at eleven thirty-five?’

‘The clock in the hall. I was watching the time because of the treasure hunt.’

‘Who won?’

‘Need you ask! The Moppett and her bully. They probably cheated in some way.’

‘Really? How do you suppose?’

‘They heard us plotting about the clues in the afternoon. The last one led back to the loo tank in the downstairs cloakroom.’

‘Here?’

‘That’s right. Most of the others guessed it but they were too late. Andrew and Nicola didn’t even try, I imagine.’

‘Any corroborative evidence, do you remember?’

‘Of my alibi?’

‘Of your alibi,’ Alleyn agreed sedately.

‘I don’t know. I think I called out something to Bimbo. He might remember.’

‘So he might. About last night’s serenade to your second husband. Did you introduce the subject of your son’s inheritance?’

She burst out laughing: she had a loud, formidable laugh like a female Duke of Wellington. ‘Do you know,’ she said, ‘I believe I did. Something of the sort. Anything to get a rise.’

‘He called on you yesterday afternoon, didn’t he?’

‘Oh, yes,’ she said quickly. ‘About Flash Len and a car. He was in a great taking-on, poor pet.’

‘And on that occasion,’ Alleyn persisted, ‘did you introduce the subject of the inheritance?’

‘Did we? Yes, so we did. I told Hal I thought he was behaving jolly shabbily which was no more than God’s truth.’

‘What was his reaction?’