That afternoon when I returned from seeing my patients, Caroline told me that Geoffrey Raymond had just left.

'Did he want to see me?' I asked.

'It was Monsieur Poirot he wanted to see,' Caroline said. 'He'd just come from The Larches. Monsieur Poirot was out and Mr Raymond thought that he might be here. He said he would come back and went away. A great pity, because Monsieur Poirot came in almost the minute after he left.'

'Came in here?'

'No, to his own house.'

'How do you know?'

'The side window,' Caroline explained. 'I can see the front door from there. Aren't you going across to The Larches?'

'My dear Caroline,' I said, 'what for?'

'You might hear what it's all about. And you might tell Monsieur Poirot about the boots.'

Poirot got up to meet me, with a look of pleasure, when I arrived at the Larches.

'Sit down, my good friend,' he said. 'You have something for me, yes?'

'Information - of a kind.'

I told him of my interview with Mrs Ackroyd.

'That explains something to me,' he said thoughtfully. 'And it confirms the evidence of the housekeeper. She said, you remember, that she found the lid of the silver table open and closed it as she walked past it.'

'Yes,' I said. 'But why did she come in through the French windows? By the way, I've got a message for you from my sister. Ralph Paton's boots were black, not brown.'

'Ah!' said Poirot sadly. 'That is a pity.'

He gave no explanation about why. Then the door opened and Geoffrey Raymond came in.

'Perhaps I'd better leave,' I suggested.

'Please don't go because of me, Doctor,' said Raymond. 'I just have a confession to make. You accused us all of hiding something, Monsieur Poirot. I plead guilty. I was in debt - badly, and Ackroyd's five hundred pounds will solve all my problems.'

He smiled with that openness that made him such a likeable youngster.

'You are a very wise young man,' said Poirot, nodding with approval. 'You see, when I know someone is hiding things from me, I suspect that the thing hidden may be something very bad indeed. You have done well.'

'I'm glad I'm cleared from suspicion,' laughed Raymond. 'I'll leave now.'

'So that is that,' I remarked, as the door closed behind the young secretary.

'Yes,' agreed Poirot. 'But have you thought, my friend, that many people in that house will benefit by Mr Ackroyd's death? Only one, in fact, does not - Major Blunt.'

The way he said Blunt's name was so strange that I looked up, puzzled.

'You think he has something to conceal also?'