‘Betty Barnard was a flirt. She liked attention from a personable male. Therefore A B C, to persuade her to come out with him, must have had a certain amount of attraction—of le sex appeal! He must be able, as you English say, to “get off”. He must be capable of the click! I visualize the scene on the beach thus: the man admires her belt. She takes it off, he passes it playfully round her neck—says, perhaps, “I shall strangle you.” It is all very playful. She giggles—and he pulls—’

Donald Fraser sprang up. He was livid.

‘M. Poirot—for God’s sake.’

Poirot made a gesture.

‘It is finished. I say no more. It is over. We pass to the next murder, that of Sir Carmichael Clarke. Here the murderer goes back to his first method—the blow on the head. The same alphabetical complex—but one fact worries me a little. To be consistent the murderer should have chosen his towns in some definite sequence.

‘If Andover is the 155th name under A, then the B crime should be the 155th also—or it should be the 156th and the C the 157th. Here again the towns seemed to be chosen in rather too haphazard a fashion.’

‘Isn’t that because you’re rather biased on that subject, Poirot?’ I suggested. ‘You yourself are normally methodical and orderly. It’s almost a disease with you.’

‘No, it is not a disease! Quelle idée! But I admit that I may be over-stressing that point. Passons!

‘The Churston crime gave me very little extra help. We were unlucky over it, since the letter announcing it went astray, hence no preparations could be made.

‘But by the time the D crime was announced, a very formidable system of defence had been evolved. It must have been obvious that A B C could not much longer hope to get away with his crimes.

‘Moreover, it was at this point that the clue of the stockings came into my hand. It was perfectly clear that the presence of an individual selling stockings on and near the scene of each crime could not be a coincidence. Hence the stocking-seller must be the murderer. I may say that his description, as given me by Miss Grey, did not quite correspond with my own picture of the man who strangled Betty Barnard.

‘I will pass over the next stages quickly. A fourth murder was committed—the murder of a man named George Earlsfield—it was supposed in mistake for a man named Downes, who was something of the same build and who was sitting near him in the cinema.

‘And now at last comes the turn of the tide. Events play against A B C instead of into his hands. He is marked down—hunted—and at last arrested.

‘The case, as Hastings says, is ended!

‘True enough as far as the public is concerned. The man is in prison and will eventually, no doubt, go to Broadmoor. There will be no more murders. Exit! Finis! R.I.P.