“I mean that this is not a crime that was committed single-handed. Two people were in it. It is quite true that you could not have typed that letter and at the same time gone to the cove—but there would have been time for you to have jotted down that letter in shorthand—and for someone else to have typed it in your room while you yourself were absent on your murderous errand.”

Hercule Poirot looked towards Rosamund Darnley. He said:

“Miss Darnley states that she left Sunny Ledge at ten minutes past eleven and saw you typing in your room. But just about that time Mr. Gardener went up to the hotel to fetch a skein of wool for his wife. He did not meet Miss Darnley or see her. That is rather remarkable. It looks as though either Miss Darnley never left Sunny Ledge, or else she had left it much earlier and was in your room typing industriously. Another point, you stated that when Miss Darnley looked into your room at a quarter past eleven you saw her in the mirror. But on the day of the murder your typewriter and papers were all on the writing desk across the corner of the room, whereas the mirror was between the windows. So that statement was a deliberate lie. Later, you moved your typewriter to the table under the mirror so as to substantiate your story—but it was too late. I was aware that both you and Miss Darnley had lied.”

Rosamund Darnley spoke. Her voice was low and clear.

She said:

“How devilishly ingenious you are!”

Hercule Poirot said, raising his voice:

“But not so devilish and so ingenious as the man who killed Arlena Marshall! Think back for a moment. Who did I think—who did everybody think—that Arlena Marshall had gone to meet that morning? We all jumped to the same conclusion. Patrick Redfern. It was not to meet a blackmailer that she went. Her face alone would have told me that. Oh no, it was a lover she was going to meet—or thought she was going to meet.

“Yes, I was quite sure of that. Arlena Marshall was going to meet Patrick Redfern. But a minute later Patrick Redfern appeared on the beach and was obviously looking for her. So what then?”

Patrick Redfern said with subdued anger:

“Some devil used my name.”

Poirot said:

“You were very obviously upset and surprised by her nonappearance. Almost too obviously, perhaps. It is my theory, Mr. Redfern, that she went to Pixy Cove to meet you, and that she did meet you, and that you killed her there as you had planned to do.”

Patrick Redfern stared. He said in his high good-humoured Irish voice:

“Is it daft you are? I was with you on the beach until I went round in the boat with Miss Brewster and found her dead.”

Hercule Poirot said: