‘Oh,’ said Julia. ‘Well—I’m glad you’re back.’

‘Yes,’ said Mrs Upjohn, ‘I am very glad too.’

They looked at each other, embarrassed. ‘What are you doing?’ said Mrs Upjohn, advancing a little closer.

‘I’m writing a composition for Miss Rich,’ said Julia. ‘She really does set the most exciting subjects.’

‘What’s this one?’ said Mrs Upjohn. She bent over.

The subject was written at the top of the page. Some nine or ten lines of writing in Julia’s uneven and sprawling hand-writing came below. ‘Contrast the Attitudes of Macbeth and Lady Macbeth to Murder’ read Mrs Upjohn.

‘Well,’ she said doubtfully, ‘you can’t say that the subject isn’t topical!’

She read the start of her daughter’s essay. ‘Macbeth,’ Julia had written, ‘liked the idea of murder and had been thinking of it a lot, but he needed a push to get him started. Once he’d got started he enjoyed murdering people and had no more qualms or fears. Lady Macbeth was just greedy and ambitious. She thought she didn’t mind what she did to get what she wanted. But once she’d done it she found she didn’t like it after all.’

‘Your language isn’t very elegant,’ said Mrs Upjohn. ‘I think you’ll have to polish it up a bit, but you’ve certainly got something there.’

II

Inspector Kelsey was speaking in a slightly complaining tone.

‘It’s all very well for you, Poirot,’ he said. ‘You can say and do a lot of things we can’t: and I’ll admit the whole thing was well stage managed. Got her off her guard, made her think we were after Rich, and then, Mrs Upjohn’s sudden appearance made her lose her head. Thank the lord she kept that automatic after shooting Springer. If the bullet corresponds—’

‘It will, mon ami, it will,’ said Poirot.

‘Then we’ve got her cold for the murder of Springer. And I gather Miss Chadwick’s in a bad way. But look here, Poirot, I still can’t see how she can possibly have killed Miss Vansittart. It’s physically impossible. She’s got a cast iron alibi—unless young Rathbone and the whole staff of the Nid Sauvage are in it with her.’

Poirot shook his head. ‘Oh, no,’ he said. ‘Her alibi is perfectly good. She killed Miss Springer and Mademoiselle Blanche. But Miss Vansittart—’ he hesitated for a moment, his eyes going to where Miss Bulstrode sat listening to them. ‘Miss Vansittart was killed by Miss Chadwick.’

‘Miss Chadwick?’ exclaimed Miss Bulstrode and Kelsey together.

Poirot nodded. ‘I am sure of it.’

‘But—why?’

‘I think,’ said Poirot, ‘Miss Chadwick loved Meadowbank too much…’ His eyes went across to Miss Bulstrode.

‘I see…’ said Miss Bulstrode. ‘Yes, yes, I see…I ought to have known.’ She paused. ‘You mean that she—?’

‘I mean,’ said Poirot, ‘that she started here with you, that all along she has regarded Meadowbank as a joint venture between you both.’

‘Which in one sense it was,’ said Miss Bulstrode.

‘Quite so,’ said Poirot. ‘But that was merely the financial aspect. When you began to talk of retiring she regarded herself as the person who would take over.’