there will be a fish

Judging by the utter lack of response to my post on the context Watson left out when he describing his time as an Army doctor (seriously, how lucky is that guy even to be alive, much less successful? And he makes for excellent h/c fodder...), I get the feeling I am alone in my obsession with Sherlock Holmes' historical context. But I will inflict this on you all anyway. :D

I'm reading an excellent book on mid-Victorian London (check out the limited preview on Google Books; the contents page alone is drool-worthy, and the writing is lively, engaging, and well-researched), and ran across this in the endnotes:

There is an intriguing story in the annals of the Bank of England relating to the sewers: the Directors had ignored an anonymous letter warning them of an imminent raid on the Bank's bullion, but they finally agreed to meet their informer, at night, in the vault where the bullion was stored. Sure enough, the miscreant emerged through the floor, before their very eyes. The Bank's records include – 'in May 1836, having reason to apprehend danger from our sewers, it was discovered that an open and unobstructed sewer led directly from the gold vaults down to Dowgate'. The informant, a working man who had heard of the plot while he was repairing the sewers, was awarded £800.

Does this remind anyone else of "The Adventure of the Red-Headed League", or what?

If Conan Doyle didn't know about that incident, I'll eat my hat (or at the very least declare it a remarkable coincidence). I mean, waiting in a bank vault full of gold for a guy who comes up through the floor in the middle of the night? That sounds pretty familiar...