He murmured:

“Pour l’amour de Dieu! Is it possible?”

Hercule Poirot got up from where he had been kneeling by the grate.

Slowly he looked round the room and this time there was an entirely new expression on his face. It was grave and almost stern.

To the left of the mantelpiece there were some shelves with a row of books. Hercule Poirot looked thoughtfully along the titles.

A Bible, a battered copy of Shakespeare’s plays, The Marriage of William Ashe, by Mrs. Humphry Ward. The Young Stepmother, by Charlotte Yonge. The Shropshire Lad. Eliot’s Murder in the Cathedral. Bernard Shaw’s St. Joan. Gone With the Wind, by Margaret Mitchell. The Burning Court, by Dickson Carr.

Poirot took out two books. The Young Stepmother and William Ashe, and glanced inside at the blurred stamp affixed to the title page. As he was about to replace them, his eye caught sight of a book that had been shoved behind the other books. It was a small dumpy volume bound in brown calf.

He took it out and opened it. Very slowly he nodded his head.

He murmured:

“So I was right… Yes, I was right. But for the other—is that possible too? No, it is not possible, unless…”

He stayed there, motionless, stroking his moustaches whilst his mind ranged busily over the problem.

He said again, softly:

“Unless—”

II

Colonel Weston looked in at the door.

“Hullo, Poirot, still there?”

“I arrive. I arrive,” cried Poirot.

He hurried out into the corridor.

The room next to Linda’s was that of the Redferns.

Poirot looked into it, noting automatically the trace of two different individualities—a neatness and tidiness which he associated with Christine, and a picturesque disorder which was characteristic of Patrick. Apart from these sidelights on personality the room did not interest him.

Next to it again was Rosamund Darnley’s room, and here he lingered for a moment in the sheer pleasure of the owner’s personality.

He noted the few books that lay on the table next to the bed, the expensive simplicity of the toilet set on the dressing table. And there came gently to his nostrils the elusive expensive perfume that Rosamund Darnley used.

Next to Rosamund Darnley’s room at the northern end of the corridor was an open window leading to a balcony from which an outside stair led down to the rocks below.

Weston said:

“That’s the way people go down to bathe before breakfast—that is, if they bathe off the rocks as most of them do.”

Interest came into Hercule Poirot’s eyes. He stepped outside and looked down.

Below, a path led to steps cut zigzag leading down the rocks to the sea. There was also a path that led round the hotel to the left. He said:

“One could go down these stairs, go to the left round the hotel and join the main path up from the causeway.”

Weston nodded. He amplified Poirot’s statement.

“One could go right across the island without going through the hotel at all.” He added: “But one might still be seen from a window.”