Summary. It was Nan Pringle, and for the plainest of reasons: she could buy every tongue in that house but his. She turned the gardener's warning card face down at the potting bench, said nothing of what she knew to the Reverend Simeon Gaunt, and let him gather his own oleander in the dark believing it peppermint. Here is how I came to it.

The Reckoning. The death itself gave up its manner easily enough. Gaunt drank nothing but his own tisane, steeped nightly at the potting-bench kettle from leaves he picked himself. The oleander stood a yard from the peppermint, both plainly labelled, but the gas at that end was kept low for the orchids' sake, and a man wanting his spectacles to read a brass plate by candlelight had left them folded in his coat pocket. He picked, he steeped, he drank, and Dr Quill named the leaf within the hour. No mark on him, no struggle, nothing composed about the body — a man killed by his own hand and someone else's silence.

The card is what closes it. It lay face down under a seed-tray, its warning hidden from any servant or guest who might have glanced at it, and the dust on its upper face lay undisturbed when the body was found at eleven. That dust had been settling some while — the card had not been turned since well before Gaunt came down. Nan had been at that bench, writing letters, from nine until a quarter past ten, and it was Nan, not Gaunt's own sister nor the Colonel, who had remarked aloud that evening to the footman that the two plants stood a yard apart and somebody ought to move one. She knew the hazard to the leaf. She left the card as she had turned it, and she went to her papers in the drawing-room, and she said not one word to the man at the kettle.

The rest of the house falls away on plain fact, and I will not linger over any of them. The Colonel was at the long table with two witnesses and his own carrying voice from a quarter to nine straight through to the alarm, and besides, he does not know one leaf in that conservatory from another. The footman Zane stood at the door with the lamp the whole evening, naming every soul who passed him and named in turn by all of them; he was never near the bench. Cousin R was arranging camellias with Effie and the doctor from ten o'clock, each vouching for the others, and in any case this was no death arranged for an audience — it was a death arranged to look like none at all, which is not his habit. Effie was in the billiard room and then the gallery, accounted for at both ends, and had no quarrel with the dead man this week; his own pocket-book named two others before her. Lady Lavinia sat behind a locked door from half nine to half ten and then sat to supper in company, and had, besides, no need of silencing her brother — he had told her himself on the Tuesday what he meant to say, and invited her to hear it. Captain Frew was in the billiard room and then the cellar under the butler's eye throughout, and it would have profited him nothing to see Gaunt dead; a year's quiet had already been bought and paid for out of the Colonel's own accounts, and a live man kept quiet costs less than a dead one investigated.

Which brings the matter to its grain. Nan keeps the Colonel's letters and his books, and twice this year the sums in those books have wandered and come home again a month later, as sums will do when a careful hand moves them. Captain Frew has known this a twelvemonth and holds his tongue for a quarterly consideration — the household's ordinary coin, and no one thinks the worse of him for taking it. Gaunt took nothing from anyone in his life, and everyone in Cairnholm knew it. He did not threaten and he did not bargain; he simply proposed to speak, aloud, before the household, on the Thursday — and his pocket-book had her initials down for it, third on his list, after the Colonel's vanity and his own sister's paid sittings. A man who cannot be bought cannot be managed by any means a woman in Nan's place has ever had at her disposal, and so she managed him the only way left to her — by doing nothing at all, at the one moment when something would have saved him. It is a tidy sort of murder, if murder can be tidy: no blow struck, no hand raised, nothing that a magistrate could point to and call an act. But the card was turned before he came down, and she is the one who turned it.

I had very nearly closed the file on the strength of that alone, and then recalled the dust. It is a small thing, a film of grey on a bit of pasteboard, but it will not be argued with: the card was already lying face down, untouched, well before Gaunt ever reached for the kettle. Whatever anyone in that house wishes to call an accident, the dust says otherwise. Nan Pringle is charged accordingly. The third this twelvemonth, by my count, and I do not expect it to be the last I am called to this house.

When all's said and counted, the deed it was done,
and Nan the answer, when answer was none.
Poor Gaunt 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.