‘Well, it’s an unpleasant thing to face, but I should say we’ve got some pathological character in this part of the world. Not a native, I hope. Perhaps been let out of an asylum – they’re always letting ’em out half-cured nowadays. What I mean is, no one would ever want to strangle that Tucker girl. There couldn’t be any motive, I mean, except some abnormal one. And if this man, whoever he is, is abnormal I should say he’s probably strangled that poor girl, Hattie Stubbs, as well. She hasn’t very much sense you know, poor child. If she met an ordinary-looking man and he asked her to come and look at something in the woods she’d probably go like a lamb, quite unsuspecting and docile.’

‘You think her body is somewhere on the estate?’

‘Yes, M. Poirot, I do. They’ll find it once they search around. Mind you, with about sixty-five acres of woodland here, it’ll take some finding, if it’s been dragged into the bushes or tumbled down a slope into the trees. What they need is bloodhounds,’ said Mrs Masterton, looking, as she spoke, exactly like a bloodhound herself. ‘Bloodhounds! I shall ring up the Chief Constable myself and say so.’

‘It is very possible that you are right, Madame,’ said Poirot. It was clearly the only thing one could say to Mrs Masterton.

‘Of course I’m right,’ said Mrs Masterton; ‘but I must say, you know, it makes me very uneasy because the fellow is somewhere about. I’m calling in at the village when I leave here, telling the mothers to be very careful about their daughters – not let ’em go about alone. It’s not a nice thought, M. Poirot, to have a killer in our midst.’

‘A little point, Madame. How could a strange man have obtained admission to the boathouse? That would need a key.’

‘Oh, that,’ said Mrs Masterton, ‘that’s easy enough. She came out, of course.’

‘Came out of the boathouse?’

‘Yes. I expect she got bored, like girls do. Probably wandered out and looked about her. The most likely thing, I think, is that she actually saw Hattie Stubbs murdered. Heard a struggle or something, went to see and the man, having disposed of Lady Stubbs, naturally had to kill her too. Easy enough for him to take her back to the boathouse, dump her there and come out, pulling the door behind him. It was a Yale lock. It would pull to, and lock.’

Poirot nodded gently. It was not his purpose to argue with Mrs Masterton or to point out to her the interesting fact which she had completely overlooked, that if Marlene Tucker had been killed away from the boathouse, somebody must have known enough about the murder game to put her back in the exact place and position which the victim was supposed to assume. Instead, he said gently: