Mrs Bantry’s finger came slowly round to Miss Marple.

‘Now then, School Marm,’ she said.

‘Sir Henry has put it all very clearly—very clearly indeed,’ said Miss Marple. ‘And Dr Lloyd was so right in what he said. Between them they seem to have made things so very clear. Only I don’t think Dr Lloyd quite realized one aspect of what he said. You see, not being Sir Ambrose’s medical adviser, he couldn’t know just what kind of heart trouble Sir Ambrose had, could he?’

‘I don’t quite see what you mean, Miss Marple,’ said Dr Lloyd.

‘You’re assuming—aren’t you?—that Sir Ambrose had the kind of heart that digitalin would affect adversely? But there’s nothing to prove that that’s so. It might be just the other way about.’

‘The other way about?’

‘Yes, you did say that it was often prescribed for heart trouble?’

‘Even then, Miss Marple, I don’t see what that leads to?’

‘Well, it would mean that he would have digitalin in his possession quite naturally—without having to account for it. What I am trying to say (I always express myself so badly) is this: Supposing you wanted to poison anyone with a fatal dose of digitalin. Wouldn’t the simplest and easiest way be to arrange for everyone to be poisoned—actually by digitalin leaves? It wouldn’t be fatal in anyone else’s case, of course, but no one would be surprised at one victim because, as Dr Lloyd said, these things are so uncertain. No one would be likely to ask whether the girl had actually had a fatal dose of infusion of digitalis or something of that kind. He might have put it in a cocktail, or in her coffee or even made her drink it quite simply as a tonic.’

‘You mean Sir Ambrose poisoned his ward, the charming girl whom he loved?’

‘That’s just it,’ said Miss Marple. ‘Like Mr Badger and his young housekeeper. Don’t tell me it’s absurd for a man of sixty to fall in love with a girl of twenty. It happens every day—and I dare say with an old autocrat like Sir Ambrose, it might take him queerly. These things become a madness sometimes. He couldn’t bear the thought of her getting married—did his best to oppose it—and failed. His mad jealousy became so great that he preferred killing her to letting her go to young Lorimer. He must have thought of it some time beforehand, because that foxglove seed would have to be sown among the sage. He’d pick it himself when the time came, and send her into the kitchen with it. It’s horrible to think of, but I suppose we must take as merciful a view of it as we can. Gentlemen of that age are sometimes very peculiar indeed where young girls are concerned. Our last organist—but there, I mustn’t talk scandal.’

‘Mrs Bantry,’ said Sir Henry. ‘Is this so?’

Mrs Bantry nodded.

‘Yes. I’d no idea of it—never dreamed of the thing being anything but an accident. Then, after Sir Ambrose’s death, I got a letter. He had left directions to send it to me. He told me the truth in it. I don’t know why—but he and I always got on very well together.’