As I was driving back from visiting my patients the following morning, I met Inspector Raglan.

'Good morning, Dr Sheppard,' said the inspector. 'I'm on my way to the Larches to let Monsieur Poirot know that he was quite right about those fingerprints. They did belong to Mr Ackroyd. However, although he was right about that, I'm afraid to say that in other ways, I don't think Poirot's mind is quite what it used to be... That's why he had to retire and come down here. It seems to be a family thing - he's got a nephew who's completely mad.'

'Poirot has?' I said, very surprised.

'Yes. Quietly behaved, I believe, but mad, poor boy.'

'Who told you that?'

A huge smile appeared on Inspector Raglan's face. 'Your sister, Miss Sheppard.'

Really, Caroline is amazing. She never rests until she knows every detail of everybody's family secrets.

'Jump in, Inspector,' I said, opening the door of my car. 'We'll go up to The Larches together, and give our Belgian friend the latest news.'

Poirot received us with his usual smiling politeness. He listened to the information we had brought him, nodding his head. Then he raised a hand.

'But you see, you approach the matter from the wrong base.'

The inspector stared at him, frowning. 'I don't understand what you mean.'

Poirot shook his head. 'Look here; you believe Mr Ackroyd was alive at a quarter to ten.'

'Well, you have to admit that too, don't you, Monsieur Poirot?'

'I admit nothing that is not - proved!' Poirot answered with a quick smile.

'Well, we've got Miss Flora Ackroyd's evidence.'

'That she said goodnight to her uncle? But me - I do not always believe what a young lady tells me.'

'But Parker saw her coming out of the door.'

'No. That is just what he did not see. Parker saw her outside the door, with her hand on the handle. He did not see her come out of the room.'

'But - where else could she have been?'

'Perhaps on the stairs. That is my little idea.'

'But those stairs only lead to Mr Ackroyd's bedroom.'

'Precisely.'

And still the inspector stared. 'You think she'd been up to her uncle's bedroom? Are you suggesting that it was Miss Ackroyd who took that forty pounds?'