Summary. It was Aziz, the Colonel's own keeping never in doubt, and he did it for the man who keeps him — here is how I came to it.

The Reckoning. The Colonel died of a single blow at the cellar stair-foot, struck with the iron decanting stand, bare-handed, by someone who set the thing down and did not linger. He lay squarely between the stair and the arch, so that whoever struck him had put himself, deliberately or not, between the body and the man behind that arch. That man was Xerxes, chalking bins since ten to nine, and he could not have come forward to strike and then retreated to his racks without stepping over the Colonel to do it; the body itself clears him. The lamp at the stair-head, trimmed high at half-past eight, was found burned down to a thread — someone had turned it low on purpose, before going down, and that is not the act of a man fetching another up to his supper. Aziz was found standing at that same stair-head at four minutes past nine, with cellar whitewash on his sleeve from elbow to cuff, though he claimed not to have gone below; the wall on that stair is the only place in the house that would leave a man so marked. He is, besides, the one soul in the establishment unplaced between twenty minutes to nine and four minutes past — every other name in the house has an alibi that holds.

The money did not point at him, nor at anyone with money to gain. Wat had been paid in full that afternoon and given a further order for the spring; nothing had worsened for him. Lavinia's retainer had just been doubled. Effie's expectations rested on a will unsigned until Thursday, and the Colonel's dying this week cost her, rather than served her. Quill and Cousin R and Lavinia sit together over the judging glasses from a quarter to nine, vouched for in a body, and neither the hour nor the instrument fits any of them regardless. Only one document in the house had gone, that very evening, from a threat spoken to a threat drawn and dated and read aloud: the marriage settlement binding Xerxes to Nan Pringle, the Colonel's own hand upon it, Martinmas named for the signing, and — spoken plainly at table — that whatever private arrangement Xerxes kept would have to be put by.

That arrangement was Aziz. He is exiled, kept, and owns nothing of his own in that house but a locket Xerxes gave him, which he has never sold and never removes; what he is to Xerxes is his own affair, and I will not set it down here, but what it drove him to is mine to report. The Colonel was not a cruel man, by every account, only a busy one, pushing a match for a month because it suited his partner's standing and his poor relation's prospects both, and never once weighing what it would cost the man who stood behind the arch. Aziz weighed it for him. He left the reading before it was finished, turned the lamp down at his leisure, went down, and struck the one man in the house who could take Xerxes from him — not the bride, who was blameless, and not Xerxes, who was never in danger from him at all, but the architect of the thing, stopped between the stair and the arch he was standing to protect. I had very nearly overlooked the small remark Mrs Sib Gow gave me, that Aziz had said that afternoon a house may take a man's money and his name and leave him his own, but must not take the man — spoken hours before he proved it. I have charged him accordingly; it is the third this twelvemonth, by my count, and I do not expect it to be the last I write from this address.

The method was quiet, the motive was plain,
and Aziz shall never be spoken again.
Here the Colonel 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.