Summary. It was Dr Quill did it, and not for any settlement or inheritance, though the house was quick enough to think so. Nan Pringle had come by a chemist's account proving he had drawn laudanum and morphia against the physician's name and never let them near her ledger, and she meant, in her own quiet way, to put it to him that week. He followed her up the cellar stair, she showed him the paper, and he shoved her down it in a fright he had never before had cause to feel with her. She struck the turn and broke her neck. That is the whole of it, and here is how I came to it.

The Reckoning. The house had its story ready to hand before I ever arrived, and it was a good one — the Colonel's settlement naming Nan mistress of the Manor, Effie's debts called in, a luncheon quarrel loud enough for the servants to carry. I have buried men on thinner motive than that. But the settlement explains why the household grieved for Nan; it does not explain who was alone with her in a blind passage at the one moment that mattered, and none of the settlement's beneficiaries or losers were anywhere near that stair. The Colonel was in the cellar from nine, choleric over the second bin, in the sight of the whole company and of Mrs Gow at the door, and never passed the stair after Nan went up. Effie sat on the steps below the turn the entire time, seen by Cousin R and the Colonel both — Nan going up past her would have been seen by everyone, and was. Lavinia went down at 9.02 and stayed below; she never climbed at all that evening. Zane was named at the cellar door at 9.12, 9.15, and 9.18 by a housekeeper who is exact to the minute and misses nothing that passes her. Cousin R sat on the bin-ledge the whole while, three witnesses to it. Wat left by the harbour hatch at 9.14, and the Colonel's groom had him at the cart until the noise came. Aziz and Xerxes sat with the Colonel's clerk in the business room from ten to nine, on venture papers, the clerk vouching for both without a break, and that room does not open onto the cellar passage at all. Every one of them accounted for, every one of them cleared not by character but by the clock.

That leaves the man who went up the stair at 9.14 on the pretext of a spectacle-case that was, the whole time, sitting in his own coat pocket. Quill is coroner for this parish and signs its certificates, including two of his own patients' this spring; he had drunk nothing that evening, though the port was laid down expressly to honour his standing invitation. A screw of chemist's paper, empty, lay dry at the head of that passage on a night when every boot in the house came in wet — dry on a wet flagstone, which I nearly overlooked, and which places a man standing there with his own hands busy, and not passing through with the crowd. Nan's ledger, which the whole house's physic went through under her own hand, showed three quantities of Dr Quill's laudanum and morphia never entered; she had written to the chemist herself on the ninth for the account, and told Mrs Gow on the eleventh that she meant to put a thing to him kindly, that week, rather than let it sit. He had called on her every week for years, and the house took it for the one gentleness either of them kept — what he was to her, and she to him, over all those years in Kirk Wynd, is their own long affair and none of mine to set down in a police file. What matters to me is only this: he is not a man who raises his voice or lifts a hand, in eleven years nobody in that house had seen him do either — and she was the one person alive who had never once frightened him, until the evening she stood in a blind passage and asked him gently to account for himself. That is the third this twelvemonth, by my count, and I am told to expect no fewer before the year is out. I have charged Dr Tobias Quill with the killing of Nan Pringle, and the file, so far as this house allows a file ever to close, is closed.

The method was quiet, the motive was plain,
and Quill shall never be spoken again.
Here Nan lies still, in a house full of eyes,
and none of them fancied a soul would be wise.
The whole sorry business we'll shelve with a shrug —
and sleep, and forget it, and think it no tug.