‘Then who did?’ said Mr Parker Pyne placidly.

Pamela came nearer. ‘Do you know what I think? She did it herself. She’s been frightfully queer lately. She used to imagine things.’

‘What things?’

‘Queer things. Basil, for instance. She was always hinting that Basil was in love with her. And Basil and I are—we are—’

‘I realize that,’ said Mr Parker Pyne, smiling.

‘All that about Basil was pure imagination. I think she had a down on poor little Nunks, and I think she made up that story and told it to you, and then put the strychnine in his cabin and in his pocket and poisoned herself. People have done things like that, haven’t they?’

‘They have,’ admitted Mr Parker Pyne. ‘But I don’t think that Lady Grayle did. She wasn’t, if you’ll allow me to say so, the type.’

‘But the delusions?’

‘Yes, I’d like to ask Mr West about that.’

He found the young man in his room. Basil answered his questions readily enough.

‘I don’t want to sound fatuous, but she took a fancy to me. That’s why I daren’t let her know about me and Pamela. She’d have had Sir George fire me.’

‘You think Miss Grayle’s theory a likely one?’

‘Well, it’s possible, I suppose.’ The young man was doubtful.

‘But not good enough,’ said Mr Parker Pyne quietly. ‘No, we must find something better.’ He became lost in meditation for a minute or two. ‘A confession would be best,’ he said briskly. He unscrewed his fountain pen and produced a sheet of paper. ‘Just write it out, will you?’

Basil West stared at him in amazement. ‘Me? What on earth do you mean?’

‘My dear young man’—Mr Parker Pyne sounded almost paternal—‘I know all about it. How you made love to the good lady. How she had scruples. How you fell in love with the pretty, penniless niece. How you arranged your plot. Slow poisoning. It might pass for natural death from gastroenteritis—if not, it would be laid to Sir George’s doing, since you were careful to let the attacks coincide with his presence.

‘Then your discovery that the lady was suspicious and had talked to me about the matter. Quick action! You abstracted some strychnine from Miss MacNaughton’s store. Planted some of it in Sir George’s cabin, and some in his pocket, and put sufficient into a cachet which you enclosed with a note to the lady, telling her it was a “cachet of dreams”.

‘A romantic idea. She’d take it as soon as the nurse had left her, and no one would know anything about it. But you made one mistake, my young man. It is useless asking a lady to burn letters. They never do. I’ve got all that pretty correspondence, including the one about the cachet.’