Chapter 2: The Pickpocket's Dangerous Knowledge

The errand that took Watson across the river on the morning of the twelfth was trivial in origin and consequential in every way that followed: a printer on Tooley Street who had, by some combination of administrative incompetence and seasonal delay, failed to deliver the cards Watson had ordered for the new office, and who had then compounded the offence by failing to reply to two successive notes. It was the sort of matter Watson would once have delegated without a second thought — to Holmes, who would have dispatched a Baker Street Irregular and had the cards in hand within the hour — and the recognition of that absence had become, in recent weeks, a reliable index of how many small reliances he had never bothered to catalogue. He crossed Blackfriars Bridge with the collar of his coat turned up against the November air, which was cold in the particular way of a city that has not yet committed to winter but is no longer pretending otherwise, and by the time he had extracted a grudging apology and a promise of delivery by the following Thursday from the printer, the morning was nearly gone.

He was returning through Bermondsey by a route that was not strictly direct when he heard it.

He heard it before he saw it: the particular acoustic signature of blows being struck against a human body, which is a sound a surgeon who has worked behind a military field line cannot mistake for anything else. It came from a yard off the alley he was cutting through, half-obscured by a cart that had been pulled sideways against the wall as though in deliberate arrangement, and Watson turned toward it without conscious decision, the way his feet had learned to move toward wounded men on the veldt before his mind had finished forming the order.