‘But she’s far too old,’ objected Miss Bulstrode.

‘Yes,’ said Poirot, ‘she is too old and she is not suited to be a headmistress. But she herself did not think so. She thought that when you went she would be headmistress of Meadowbank as a matter of course. And then she found that was not so. That you were considering someone else, that you had fastened upon Eleanor Vansittart. And she loved Meadowbank. She loved the school and she did not like Eleanor Vansittart. I think in the end she hated her.’

‘She might have done,’ said Miss Bulstrode. ‘Yes, Eleanor Vansittart was—how shall I put it?—she was always very complacent, very superior about everything. That would be hard to bear if you were jealous. That’s what you mean, isn’t it? Chaddy was jealous.’

‘Yes,’ said Poirot. ‘She was jealous of Meadowbank and jealous of Eleanor Vansittart. She couldn’t bear the thought of the school and Miss Vansittart together. And then perhaps something in your manner led her to think that you were weakening?’

‘I did weaken,’ said Miss Bulstrode. ‘But I didn’t weaken in the way that perhaps Chaddy thought I would weaken. Actually I thought of someone younger still than Miss Vansittart—I thought it over and then I said No, she’s too young…Chaddy was with me then, I remember.’

‘And she thought,’ said Poirot, ‘that you were referring to Miss Vansittart. That you were saying Miss Vansittart was too young. She thoroughly agreed. She thought that experience and wisdom such as she had got were far more important things. But then, after all, you returned to your original decision. You chose Eleanor Vansittart as the right person and left her in charge of the school that weekend. This is what I think happened. On that Sunday night Miss Chadwick was restless, she got up and she saw the light in the squash court. She went out there exactly as she says she went. There is only one thing different in her story from what she said. It wasn’t a golf club she took with her. She picked up one of the sandbags from the pile in the hall. She went out there all ready to deal with a burglar, with someone who for a second time had broken into the Sports Pavilion. She had the sandbag ready in her hand to defend herself if attacked. And what did she find? She found Eleanor Vansittart kneeling down looking in a locker, and she thought, it may be—(for I am good,’ said Hercule Poirot in a parenthesis, ‘—at putting myself into other people’s minds—) she thought if I were a marauder, a burglar, I would come up behind her and strike her down. And as the thought came into her mind, only half conscious of what she was doing, she raised the sandbag and struck. And there was Eleanor Vansittart dead, out of her way. She was appalled then, I think, at what she had done. It has preyed on her ever since—for she is not a natural killer, Miss Chadwick. She was driven, as some are driven, by jealousy and by obsession. The obsession of love for Meadowbank. Now that Eleanor Vansittart was dead she was quite sure that she would succeed you at Meadowbank. So she didn’t confess. She told her story to the police exactly as it had occurred but for the one vital fact, that it was she who had struck the blow. But when she was asked about the golf club which presumably Miss Vansittart took with her being nervous after all that had occurred, Miss Chadwick said quickly that she had taken it out there. She didn’t want you to think even for a moment that she had handled the sandbag.’