'I am answered,' said Poirot, with a curious laugh. He got up from his seat. 'I appeal to you all. Tell me the truth - the whole truth.' There was a silence. 'Will no one speak?' He gave the same short laugh again.

'C'est dommage,' he said, and went out.

That evening, at Poirot's request, I went over to his house after dinner. Caroline saw me depart with visible reluctance.

I think she would have liked to have accompanied me.

Poirot greeted me hospitably. He had placed a bottle of Irish whiskey (which I detest) on a small table, with a soda water siphon and a glass. He himself was engaged in brewing hot chocolate. It was a favourite beverage of his, I discovered later.

He inquired politely after my sister, whom he declared to be a most interesting woman.

'I'm afraid you've been giving her a swelled head,' I said drily. 'What about Sunday afternoon?' He laughed and twinkled.

'I always like to employ the expert,' he remarked obscurely, but he refused to explain the remark.

'You got all the local gossip anyway,' I remarked. 'True, and untrue.' 'And a great deal of valuable information,' he added quietly.

'Such as-' He shook his head.

'Why not have told me the truth?' he countered. 'In a place like this, all Ralph Paton's doings were bound to be known. If your sister had not happened to pass through the wood that day somebody else would have done so.' 'I suppose they would,' I said grumpily. 'What about this interest of yours in my patients?' Again he twinkled.

'Only one of them, doctor. Only one of them.' 'The last?' I hazarded.

He held out to me the little quill. I looked at it curiously.

Then a memory of something I had read stirred in me.

Poirot, who had been watching my face, nodded.

'Yes, heroin, "snow." Drug-takers carry it like this, and sniff it up the nose.' 'Diamorphine hydrochloride,' I murmured mechanically.

'This method of taking the drug is very common on the other side. Another proof, if we wanted one, that the man came from Canada or the States.' 'What first attracted your attention to that summerhouse?' I asked curiously.

'My friend the inspector took it for granted that anyone using that path did so as a short cut to the house, but as soon as I saw the summer-house, I realized that the same path would be taken by anyone using the summer-house as a rendezvous. Now it seems fairly certain that the stranger came neither to the front nor to the back door. Then did someone from the house go out and meet him? If so, what could be a more convenient place than that little summerhouse?

I searched it with the hope that I might find some clue inside. I found two, the scrap of cambric and the quill.' 'And the scrap of cambric?' I asked curiously. 'What about that?' Poirot raised his eyebrows.

'You do not use your little grey cells,' he remarked drily.

'The scrap of starched cambric should be obvious.' 'Not very obvious to me.' I changed the subject. 'Anyway,' I said, 'this man went to the summer-house to meet somebody. Who was that somebody?' 'Exactly the question,' said Poirot. 'You will remember that Mrs Ackroyd and her daughter came over from Canada to live here?' 'Is that what you meant today when you accused them of hiding the truth?' 'Perhaps. Now another point. What did you think of the parlourmaid's story?' 'What story?' 'The story of her dismissal. Does it take half an hour to dismiss a servant? Was the story of those important papers a likely one? And remember, though she says she was in her bedroom from nine-thirty until ten o'clock, there is no one to confirm her statement.' 'You bewilder me,' I said.

'To me it grows clearer. But tell me now your own ideas and theories.' I drew a piece of paper from my pocket.

'I just scribbled down a few suggestions,' I said apologetically.

'But excellent - you have method. Let us hear them.' I read out in a somewhat embarrassed voice.

'To begin with, one must look at the thing logically ' 'Just what my poor Hastings used to say,' interrupted Poirot, 'but alas! he never did so.' 'Point No. 1. - Mr Ackroyd was heard talking to someone at half-past nine.

'Point No. 2. - At some time during the evening Ralph Paton must have come in through the window, as evidenced by the prints of his shoes.

'Point No. 3. - Mr Ackroyd was nervous that evening, and would only have admitted someone he knew.

'Point No. 4. - The person with Mr Ackroyd at nine-thirty was asking for money. We know Ralph Paton was in a scrape.

' These four points go to show that the person with Mr Ackroyd at nine-thirty was Ralph Paton. But we know that Mr Ackroyd was alive at a quarter to ten, therefore it was not Ralph who killed him. Ralph left the window open. Afterwards the murderer came in that way.' 'And who was the murderer?' inquired Poirot.

'The American stranger. He may have been in league with Parker, and possibly in Parker we have the man who blackmailed Mrs Ferrars. If so, Parker may have heard enough to realize the game was up, have told his accomplice s0, and the latter did the crime with the dagger which Parker gave him.' 'It is a theory that,' admitted Poirot. 'Decidedly you have tells of a kind. But it leaves a good deal unaccounted for.' 'Such as ' 'The telephone call, the pushed-out chair ' 'Do you really think that latter important?' I interrupted.

'Perhaps not,' admitted my friend. 'It may have been pulled out by accident, and Raymond or Blunt may have shoved it into place unconsciously under the stress of emotion. Then there is the missing forty pounds.' 'Given by Ackroyd to Ralph,' I suggested. 'He may have reconsidered his first refusal.' 'That still leaves one thing unexplained.' 'What?' 'Why was Blunt so certain in his own mind that it was Raymond with Mr Ackroyd at nine-thirty?' 'He explained that,' I said.

'You think so? I will not press the point. Tell me, instead, what were Ralph Paton's reasons for disappearing?' 'That's rather more difficult,' I said slowly. 'I shall have to speak as a medical man. Ralph's nerves must have gone phut! If he suddenly found out that his uncle had been murdered within a few minutes of his leaving him - after, perhaps, a rather stormy interview - well, he might get the wind up and clear right out. Men have been known to do that - act guiltily when they're perfectly innocent.' 'Yes, that is true,' said Poirot. 'But we must not lose sight of one thing.' 'I know what you're going to say,' I remarked: 'motive. Ralph Paton inherits a great fortune by his uncle's death.' 'That is one motive,' agreed Poirot.

'One?' 'Mais oui. Do you realize that there are three separate motives staring us in the face. Somebody certainly stole the blue envelope and its contents. That is one motive.

Blackmail! Ralph Paton may have been the man who blackmailed Mrs Ferrars. Remember, as far as Hammond knew, Ralph Paton had not applied to his uncle for help of late. That looks as though he were being supplied with money elsewhere. Then there is the fact that he was in some - how do you say - scrape? - which he feared might get to his uncle's ears. And finally there is the one you have just mentioned.' 'Dear me,' I said, rather taken aback. 'The case does seem black against him.' 'Does it?' said Poirot. 'That is where we disagree, you and I. Three motives - it is almost too much. I am inclined to believe that, after all, Ralph Paton is innocent.' After the evening talk I have just chronicled, the affair seemed to me to enter on a different phase. The whole thing can be divided into two parts, each clear and distinct from the other. Part I ranges from Ackroyd's death on the Friday evening to the following Monday night. It is the straightforward narrative of what occurred, as presented to Hercule Poirot. I was at Poirot's elbow the whole time. I saw what he saw. I tried my best to read his mind. As I know now, I failed in this latter task. Though Poirot showed me all his discoveries - as, for instance, the gold wedding-ring - he held back the vital and yet logical impressions that he formed. As I came to know later, this secrecy was characteristic of him. He would throw out hints and suggestions, but beyond that he would not go.