‘Not for a moment or two,’ said Bland. ‘I’d like to find out a little more first. When did you yourself last see Lady Stubbs?’

Poirot cast his mind back. He found it difficult to remember exactly. He recalled vague glimpses of her tall, cyclamen-clad figure with the drooping black hat moving about the lawn talking to people, hovering here and there; occasionally he would hear that strange laugh of hers, distinctive amongst the many other confused sounds.

‘I think,’ he said doubtfully, ‘it must have been not long before four o’clock.’

‘And where was she then, and who was she with?’

‘She was in the middle of a group of people near the house.’

‘Was she there when De Sousa arrived?’

‘I don’t remember. I don’t think so, at least I did not see her. Sir George told De Sousa that his wife was somewhere about. He seemed surprised, I remember, that she was not judging the Children’s Fancy Dress, as she was supposed to do.’

‘What time was it when De Sousa arrived?’

‘It must have been about half-past four, I should think. I did not look at my watch so I cannot tell you exactly.’

‘And Lady Stubbs had disappeared before he arrived?’

‘It seems so.’

‘Possibly she ran away so as not to meet him,’ suggested the inspector.

‘Possibly,’ Poirot agreed.

‘Well, she can’t have gone far,’ said Bland. ‘We ought to be able to find her quite easily, and when we do…’ He broke off.

‘And supposing you don’t?’ Poirot put the question with a curious intonation in his voice.

‘That’s nonsense,’ said the inspector vigorously. ‘Why? What d’you think’s happened to her?’

Poirot shrugged his shoulders.

‘What indeed! One does not know. All one does know is that she has – disappeared!’

‘Dash it all, M. Poirot, you’re making it sound quite sinister.’

‘Perhaps it is sinister.’

‘It’s the murder of Marlene Tucker that we’re investigating,’ said the inspector severely.

‘But evidently. So – why this interest in De Sousa? Do you think he killed Marlene Tucker?’

Inspector Bland replied irrelevantly:

‘It’s that woman!’

Poirot smiled faintly.

‘Mrs Oliver, you mean?’

‘Yes. You see, M. Poirot, the murder of Marlene Tucker doesn’t make sense. It doesn’t make sense at all. Here’s a nondescript, rather moronic kid found strangled and not a hint of any possible motive.’

‘And Mrs Oliver supplied you with a motive?’

‘With a dozen at least! Amongst them she suggested that Marlene might have a knowledge of somebody’s secret love affair, or that Marlene might have witnessed somebody being murdered, or that she knew where a buried treasure was hidden, or that she might have seen from the window of the boathouse some action performed by De Sousa in his launch as he was going up the river.’

‘Ah. And which of those theories appeals to you, mon cher?’