Summary. It was Fifi, the housemaid, and she killed to stay unseen; here is how I came to it.

The Reckoning. The whole of Cousin R's existence at Cruikshank Manor was the collection of what people did not wish known, kept cold and never sold, which made him harmless to most of the household and lethal to one. That afternoon he had sat in the servants' hall watching Fifi and Zane, looking from one face to the other as a man compares two proofs of an engraving, and he had gone away with something worth writing down. What he wrote was a surname, Swann, and under it two small studies of a face, nearly identical, with a note on the set of the ears. That is not a man noting a resemblance between two servants. That is a man who has worked out that two servants are twins travelling under a name that is not their own, and has begun to set the true one to paper. For most of the house, Cousin R's watching was a nuisance one endured over the port. For a girl whose whole safety lay in being nobody in particular, it was the end of her.

The method bears out the motive. The passage lamp is turned low at a fixed hour, a fact known to anyone who works that part of the house and to no guest. Fifi, sent up with the withdrawing-room tray, had the means and the excuse to be in that passage at the hour it went dark. She took the Colonel's shell-case trophy from the hall table, handled it through his polishing-rag so as to leave nothing of her own hand on it, and waited. When Cousin R came through, she struck him once from behind, took back what she could of the memorandum-book's meaning, and left in haste — leaving the book itself, the rag, and, most tellingly, a hat. The hat was Zane's, off-duty pattern, dropped some feet from the body. It was no accident of a struggle; it was planted, so that a servant glancing into the dark would read a man's shape and a footman's hat and settle on the wrong twin. It is a cousin's trick in a house of twins, run by the one person with reason to run it.

The others fall away cleanly enough. Zane stood at his post serving port throughout the toasts, under the Colonel's eye and Quill's. The Colonel, Xerxes, Aziz, Wat, and Dr Quill sat together over the decanter from the withdrawal to the alarm, each vouching for the rest. Gaunt was at his parish lodging at prayer, his curate for witness, and never came near the house that night. Nan had rung for tea and was answered by the parlourmaid in the morning-room minutes before the body was found. Lavinia sat arranging her cards under the eyes of two of the company without a break, and Effie sat with her, vouched by Lavinia and another. Of Fifi alone, between the tray going up and the alarm going out, the house could say nothing — which is exactly the condition she had spent her service cultivating, and the one thing, this once, that told against her.

What she and her brother were called before they came to the coast, and why the name wanted burying, is their own history and none of mine to set down here. It is enough that Cousin R had found the thread and begun, in his patient cold way, to pull it, and that the girl who lived by not being looked at could not afford to let him finish. The third this twelvemonth, by my count, and I have told the Colonel I do not expect it to be the last. Fifi is charged with the wilful killing of Cousin R, and the matter, so far as this house permits anything to be finished, is closed.

Fifi, with a tray, made the dim passage bright,
While Cousin R was sent from the world that night.
The brass shell-case waited where the household trod,
And a hat made the footman of somebody odd.
The moral, we vow, is to look twice at a face—
But dinner is ready, so kindly make place.