'You will be making inquiries at the station?' I asked.

'Naturally, but you know what that station is like,' replied Colonel Melrose.

I did. King's Abbot's station is an important one where different railway lines meet. It has two public telephone boxes. At that time of night, three local trains come in to deliver passengers to the express for Liverpool, which comes in at 10.19 and leaves at 10.23. The chances of someone being noticed telephoning or getting on to the express are very small indeed.

'But why telephone at all?' demanded Melrose. 'There seems no reason.'

'Be sure there was a reason,' Poirot said. 'And when we know that, we will know everything. We should find out if Mr Ackroyd had been visited by any strangers during the past week.'

Colonel Melrose went in search of Raymond, and I rang the bell for Parker. When Geoffrey Raymond came in, he seemed delighted to meet Poirot.

'It will be a great privilege to watch you at work,' he said. Then, 'Hello, what's this?'

Poirot had moved aside and I saw that while my back had been turned, he had pulled out the armchair so that it stood in the position Parker had indicated.

'Monsieur Raymond, this chair was pulled out - like this - last night when Mr Ackroyd was found killed. Someone moved it back into its place. Did you move it back?'

'No. I don't even remember that it was in that position.'

'It is of no importance,' said the detective as Parker came in. 'What I really want to ask you is this: did any stranger come to see Mr Ackroyd during this past week?'

'No,' said Raymond. 'I can't remember anyone. Can you, Parker?'

'There was the young man who came on Wednesday, Sir,' he said. 'From Curtis and Trout, I understood he was.'

'Oh! That is not the kind of stranger this gentleman means.' Raymond turned to Poirot. 'Mr Ackroyd had some idea of buying a Dictaphone. The firm sent down their salesman, but Mr Ackroyd did not buy.'

The butler spoke to Raymond. 'Mr Hammond has just arrived, Sir.'

'I'll come at once,' said the young man.

Poirot looked inquiringly at the Chief Constable.

'Mr Hammond is the family lawyer, Monsieur Poirot.'

Poirot nodded. 'Could you please show me the table from which the dagger was taken?'