A young woman as unlike the type of his victims as could well be imagined - cool, calm, passionless, but steadfastly loyal to him and an actress of no mean ability.
From the time of her arrival here Christine Redfern played the part, the part of the 'poor little wife' - frail, helpless, an intellectual rather than athletic.
Think of the points she made one after another. Her tendency to blister in the sun and her consequent white skin, her giddiness at heights - stories of getting stuck on Milan Cathedral, etc.
An emphasis on her frailty and delicacy - nearly every one spoke of her as a 'little woman.'
She was actually as tall as Arlena Marshall but with very small hands and feet.
She spoke of herself as a former schoolteacher and thereby emphasized an impression of book learning and lack of athletic prowess.
Actually it is quite true that she had worked in a school, but the position she held there was that of games mistress and she was an extremely active young woman who could climb like a cat and run like an athlete.
"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 some one had gone for an early bathe).
Under his bathingwrap 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 any one 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.
When 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 at the cove underneath the ladder.
On Linda's return Christine easily arranged an outing together to Gull Cove. She then returned to her own room, took out from a locked suitcase a bottle of artificial suntan, applied it carefully and threw the empty bottle out of the window where it narrowly escaped hitting Emily Brewster who was bathing.
Part III successfully accomplished.
"Christine then dressed herself in a white bathing-suit and over it a pair of beach trousers and coat with long floppy sleeves which effectually concealed her newly browned arms and legs.
At 10.15 Arlena departed for her rendezvous, a minute or two later Patrick Redfern came down and registered surprise, annoyance, etc.
Christine's task was easy enough.
Keeping her own watch concealed she asked Linda at twenty-five past eleven what time it was.
Linda looked at her watch and replied that it was a quarter to twelve.
She then starts down to the sea and Christine packs up her sketching things.
As soon as Linda's back is turned Christine picks up the girl's watch which she had necessarily discarded before going into the sea and alters it back to the correct time.
Then she hurries up the cliff path, runs across the narrow neck of land to the top of the ladder, strips off her pyjamas and shoves them and her sketching box behind a rock and swarms rapidly down the ladder in her best gymnastic fashion.
"Arlena is on the beach below wondering why Patrick is so long in coming.
She sees or hears some one on the ladder, takes a cautious observation and to her annoyance sees that inconvenient person - the wife!
She hurries along the beach and into the Pixy's Cave.
"Christine takes the hat from its hiding-place, a false red curl pinned underneath the brim at the back, and disposes herself in a sprawling attitude with the hat and curl shielding her face and neck.
The timing is perfect.