“The crime itself was perfectly planned and timed. It was, as I mentioned before, a very slick crime. The timing was a work of genius.

“First of all there were certain preliminary scenes—one played on the cliff ledge when they knew me to be occupying the next recess—a conventional jealous wife dialogue between her and her husband. Later she played the same part in a scene with me. At the time I remember a vague feeling of having read all this in a book. It did not seem real. Because, of course, it was not real. Then came the day of the crime. It was a fine day—an essential. Redfern’s first act was to slip out very early—by the balcony door which he unlocked from the inside (if found open it would only be thought someone had gone for an early bathe). Under his bathing wrap he concealed a green Chinese hat, the duplicate of the one Arlena was in the habit of wearing. He slipped across the island, down the ladder and stowed it away in an appointed place behind some rocks. Part I.

“On the previous evening he had arranged a rendezvous with Arlena. They were exercising a good deal of caution about meeting as Arlena was slightly afraid of her husband. She agreed to go round to Pixy Cove early. Nobody went there in the morning. Redfern was to join her there, taking a chance to slip away unobtrusively. If she heard anyone descending the ladder or a boat came in sight she was to slip inside the Pixy’s Cave, the secret of which he had told her, and wait there until the coast was clear. Part II.

“In the meantime Christine went to Linda’s room at a time when she judged Linda would have gone for her early morning dip. She would then alter Linda’s watch, putting it on twenty minutes. There was, of course, a risk that Linda might notice her watch was wrong, but it did not much matter if she did. Christine’s real alibi was the size of her hands which made it a physical impossibility for her to have committed the crime. Nevertheless, an additional alibi would be desirable. Then in Linda’s room she noticed the book on witchcraft and magic, open at a certain page. She read it, and when Linda came in and dropped a parcel of candles she realized what was in Linda’s mind. It opened up some new ideas to her. The original idea of the guilty pair had been to cast a reasonable amount of suspicion on Kenneth Marshall, hence the abstracted pipe, a fragment of which was to be planted on the Cove underneath the ladder.