Summary. It was Miss Strange, and not for appetite but for arithmetic; she had taken a month's supply of the Captain's opium from his strongbox and could neither pay for it nor let it stand entered against her name, and so she put him beyond collecting the debt.

The Reckoning. The rum told the tale before the ledger confirmed it. Into that one bottle went laudanum enough for weeks of any honest dispensing — a quantity no genuine poisoner spends in a single dose, and no man's constitution survives. That extravagance is itself the signature. A physician working from his own cabinet measures with care, knowing his stock will be counted against him; only a thief who had already taken the whole month's worth, and owed nothing further to conscience or cabinet, could afford to be so free with it. The Captain's stock-book showed a withdrawal of a month's supply with no payment set against it, and his strongbox was short by that same quantity. The dressmaker's errand that gave Miss Strange her afternoon was a fiction — the shop stood closed for a funeral that day, a fact she herself confirmed without meaning to — and it was in that borrowed hour that she came up the garden stair, past the porter's notice entirely, and emptied her theft into his rum before it went up at six. She was gone well before the hour struck.

Dr Quill wore the look of the obvious hand, being the ablest compounder in the town and the source of every drop of laudanum in that house by rights. But his cabinet counted clean against his dispensing-book to the drachm; no such quantity had left his stock. He had, besides, engaged the Captain to fetch him port-wine from the Douro on the next run, an order entered plainly in the sailing-book — a man does not poison the ship's master he is waiting on. And he was through the door and gone within the half-hour after four, well shy of the six o'clock rum.

Lady Lavinia's spite was real enough and never disguised, but the packet of untouched money on the table answered exactly to the sum standing against her account in the Captain's own book — her debt was settled, not owing, and there was nothing left for her to bury. Her bell rang for tea at seven, placing her in her rooms across the fatal hour, and her cordial is a drop-vial, not a bottle to drown a man in.

The Reverend Gaunt was not admitted until half past seven, by the porter's own book, a full hour and more after the rum had gone up and done its work; a man cannot poison what is already emptied.

Xerxes and his companion Aziz spent the afternoon at badminton and the evening at whist at the club, the one account confirming the other, and neither had cause to wish the Captain dead — Xerxes needed him alive and civil for the morning's shipping business. The Colonel passed the whole day at Cruikshank Manor, disputing Home Rule with Cousin R before witnesses enough to fill a jury box, and never came near Hartfield House.

What Wat was to her in trade, and what she owed him, is a plainer matter than what some households make of debt; she had borrowed against his stock and could not settle, and rather than see the reckoning entered she saw that he never rose to collect it. The charge is laid. This makes the third corpse out of that house in a twelvemonth, by my count, and I do not expect it to be the last I am called to.

In arithmetic of loss dwelt Effie,
Wat swallowed poison mixed so smooth and effy.
She'd timed it for his habit and his thirst,
The servants blamed the heart that chose to burst.
What theft once hidden now lies buried too—
We'll trust the rum we drink, as people do.