Summary. It was Wat, and for the plainest of trades: a man who lives by other men's secrets found that his own was for sale, and stopped the seller's mouth before she could name her price. Here is how I came to it.

The Reckoning. The gallery told its own story before anyone spoke. Fifi died between eight and nine, in a room emptied by the tea-bell and darkened by a lamp carried out and left warm in the corridor — the trap of a man who does not care to look at his work. The twine was tarred stock brought up from the harbour that afternoon, and the knot at the nape was a doubled running hitch, cargo-work, the sort a man ties who has spent his life lashing a boat and never learned another way to finish a job. The Colonel said as much himself, twice, without knowing what he said.

The paper in her apron pocket was the true ledger. Five sets of initials, sums in shillings, two struck through — W.F. and L.L. Wat's own payers, and two of them lately stopped paying him, each telling the Colonel privately of a cheaper rival with the same information. That is not a maid's gossip; that is a competitor's book. Fifi had not merely talked, which was her old and tolerated failing — she had gone into his trade and undercut him, and had lately learned, on her own account, of the harbour-wall arrangement his whole living depends upon, and had told Mrs Gow, cheerfully, that she meant to keep it rather than sell it to him. That is the one secret in the house that could ruin Wat entire, and she was the only person holding it.

The rest fall away on plain fact, not suspicion. Lavinia was pinned into her costume in the small drawing-room from eight until the bell, the Colonel and Mrs Gow both swearing to it, and the one secret of hers Fifi held — the Friday walks — she had never once traded; there was nothing there to kill for. Zane was belowstairs under Mrs Gow's eye the whole hour, carrying tea things, and is besides the one soul whose business Fifi kept entirely to herself, having been told by him to burn the paper rather than use it. Cousin R was in the library with Effie the whole window, each vouching the other, and in any case the drapery was left merely smoothed, the knot crude — not the work of a man who spends his afternoons setting plinths to the inch. The Colonel was in the drawing-room with Lavinia and Mrs Gow throughout, and it was he, unprompted, who named the knot for a mooring hitch — an odd thing for a guilty man to point out. Dr Quill was at a confinement in the fisher-cottages from twenty to eight, under the sight of a midwife and two of the family, and was not under this roof at all when Fifi died.

Wat claims the stable door from a quarter past eight. Nobody stands beside him there. Mrs Gow saw him at the gallery doorway at half past, and took him for a man waiting on his employer, which he was not. He had cut the twine, done the thing, and straightened the drapery after — a small tidiness, oddly, from a man who otherwise took the paper for idle chatter and left it where she'd put it, not troubling to search her. That carelessness is the one thing very nearly caught me: he did not know, until I showed him, that she had written his initials down at all. He killed her for what she'd learned, and never learned himself what she'd already set to paper.

The third this twelvemonth, by my count, and this one uglier than most for being so purely a matter of trade — one secret-monger silencing another over the same coin. I have charged him. The harbour-wall arrangement, and what it was worth to him, is a matter I leave to the excise; the strangling is mine, and it is closed.

It fell out, in the end, as the cruellest of fate,
with Wat the reason, and reason came late.
Now Fifi is gathered, a held, careful breath,
one more of the twelve to the ledger of death.
The moral, we're certain, is worth the whole cost —
then shrug, and forget it, and reckon naught lost.