Summary. It was Dr Quill, and not for gain nor grudge but out of plain terror — the fear of a man who could not tell what another man knew, and killed to be safe rather than sorry. Here is how I came to it.

The Reckoning. The medicine of it was the whole of the crime. A physician who is also the coroner need only be careful once: careful with the dose, careful with the certificate, and the thing is closed before it is opened. Cousin R died in his chair during the twenty-two minutes of lantern-dark, upright, hands folded, glass empty at his elbow, not a thread of his collar disturbed. Quill was nearest when the curtains were drawn, went to him, and pronounced a failure of the heart — his own finding, entered in his own hand, in a county where his certificate ends the matter and no body he signs for may be opened again without his leave. That is not a doctor's diagnosis. That is a doctor covering his tracks with his own authority.

The rest of the house may be dismissed quickly, and I will not linger over any of them, having better things to do with an evening than count alibis twice. Xerxes was heard correcting the Colonel on his slides from the front row at the very minutes in question — a voice two rows and an aisle from the dosing, which will not travel backward through a dark room. Fifi was at the still-room sink with Mrs Gow beside her the whole while, and never in the drawing-room at all that night, light or dark. Zane had carried his last glass before the lantern was lit and stood at the front door taking in a coal delivery with two witnesses to it; a man cannot pour a doctored glass from a hallway. Lavinia's pencil ran on unbroken across the Colonel's programme, dated slide by slide, which fixes her hands in her own chair at the back throughout. Effie was at the linen-press with the under-parlourmaid talking at her elbow from 8:35 to the lamps' rising. Gaunt was in the chapel passage with the mason and a candle, measuring a tablet, from 8:20 on. Every one of them is placed by somebody with no reason to lie for them. Only Quill was where the thing was done, with the means in his hand and reason enough, once you have the reason, to want it done quickly.

The reason is a small, sad one, and does no credit to anybody. Three years since Quill certified a Miss Trembles of Cairnholm as dead of a failing heart, a certificate that has never once been questioned and never once needed to be, until a slip of paper turned up in a dead man's pocket-book bearing that single word. Cousin R had noticed it — that much the slip proves, and no more. He had held things on half the house for eleven days and traded on none of them; he was, by every account but Quill's frightened one, the one man at Cruikshank Manor who was never going to speak. But Quill could not read him — nobody could — and a man who cannot read a threat will supply one himself, out of whole cloth, rather than sit and wait to learn if it is real. He moved the bottle in his bag from the second row of the case to the first before he ever left his own surgery that morning; he had made up his mind before he sat down to supper. He dosed the glass at R's elbow in the lantern-dark, sat back down, and when the lamps came up did what he does best — pronounced, and wrote, and closed the file.

I had near forgot the small matter of the pocket-book. Quill went through it during his examination and left it on the mantel, open at a blank leaf, having found nothing worth the taking — only a ticket and that one word. He might have burned it and slept easier for it. That he did not is the measure of the man: he had already dressed the death, and a coroner's hands do not shake at evidence, only at what he imagines it might have meant. It meant nothing. R had asked him an idle question in a hallway once, and a frightened man built a scaffold on it and hanged an innocent conversation for a crime it never intended.

That is the third this twelvemonth, by my count, out of this one unhappy house, and I do not expect it to be the last. I am charging Dr Tobias Quill with the wilful murder of the man the household called Cousin R, and with the false certification of his own crime. The file closes here.

When all's said and counted, the deed it was done,
and Quill the answer, when answer was none.
Poor Cousin R lies quiet, a candle, a knife,
the tidiest exit from Cairnholm and life.
The lesson is here, should we trouble to learn —
but the cards, being cards, will be dealt a fresh turn.