‘I see,’ said Poirot. ‘As you say, it is odd…Because, as you have just told me, there was a gas fire in her room.’

Jane Plenderleith looked at him, slightly startled.

‘Yes, there was…I can’t understand—no, I can’t understand why she didn’t do it that way.’

Poirot shook his head.

‘Yes, it seems—odd—not natural somehow.’

‘The whole thing doesn’t seem natural. I still can’t believe she killed herself. I suppose it must be suicide?’

‘Well, there is one other possibility.’

‘What do you mean?’

Poirot looked straight at her.

‘It might be—murder.’

‘Oh, no?’ Jane Plenderleith shrank back. ‘Oh no! What a horrible suggestion.’

‘Horrible, perhaps, but does it strike you as an impossible one?’

‘But the door was locked on the inside. So was the window.’

‘The door was locked—yes. But there is nothing to show if it were locked from the inside or the outside. You see, the key was missing.’

‘But then—if it is missing…’ She took a minute or two. ‘Then it must have been locked from the outside. Otherwise it would be somewhere in the room.’

‘Ah, but it may be. The room has not been thoroughly searched yet, remember. Or it may have been thrown out of the window and somebody may have picked it up.’

‘Murder!’ said Jane Plenderleith. She turned over the possibility, her dark clever face eager on the scent. ‘I believe you’re right.’

‘But if it were murder there would have been a motive. Do you know of a motive, mademoiselle?’

Slowly she shook her head. And yet, in spite of the denial, Poirot again got the impression that Jane Plenderleith was deliberately keeping something back. The door opened and Japp came in.

Poirot rose.

‘I have been suggesting to Miss Plenderleith,’ he said, ‘that her friend’s death was not suicide.’

Japp looked momentarily put out. He cast a glance of reproach at Poirot.

‘It’s a bit early to say anything definite,’ he remarked. ‘We’ve always got to take all possibilities into account, you understand. That’s all there is to it at the moment.’

Jane Plenderleith replied quietly.

‘I see.’

Japp came towards her.

‘Now then, Miss Plenderleith, have you ever seen this before?’

On the palm of his hand he held out a small oval of dark blue enamel.

Jane Plenderleith shook her head.

‘No, never.’

‘It’s not yours nor Mrs Allen’s?’

‘No. It’s not the kind of thing usually worn by our sex, is it?’

‘Oh! so you recognize it.’

‘Well, it’s pretty obvious, isn’t it? That’s half of a man’s cuff link.’

Chapter 4

‘That young woman’s too cocky by half,’ Japp complained.

The two men were once more in Mrs Allen’s bedroom. The body had been photographed and removed and the fingerprint man had done his work and departed.

‘It would be unadvisable to treat her as a fool,’ agreed Poirot. ‘She most emphatically is not a fool. She is, in fact, a particularly clever and competent young woman.’

‘Think she did it?’ asked Japp with a momentary ray of hope. ‘She might have, you know. We’ll have to get her alibi looked into. Some quarrel over this young man—this budding M.P. She’s rather too scathing about him, I think! Sounds fishy. Rather as though she were sweet on him herself and he’d turned her down. She’s the kind that would bump anyone off if she felt like it, and keep her head while she was doing it, too. Yes, we’ll have to look into that alibi. She had it very pat and after all Essex isn’t very far away. Plenty of trains. Or a fast car. It’s worth while finding out if she went to bed with a headache for instance last night.’