The Spider by Fergus Hume — Read

Vernon had his doubts as to the success of Mr. Dimsdale's scheme. The Spider, as the authorities very well knew, was a wary individual, and in all dealings with his victims had been careful to provide for his own safety. He certainly met them at duly-appointed places, disguised as an old woman or a young man, as a navvy or as a foreigner; but none of those he intimidated dared to call in the police. The reason was that The Spider invariably advised them beforehand by letter that his accomplice held the evidence of the secrets for which they were being blackmailed, and that any proceedings being taken would result in the publication of these by cards being sent to their friends and relatives and acquaintances. It therefore can easily be guessed that no one had the courage to lay the rogue by the heels.

But, as it appeared, The Spider had, in Mr. Dimsdale, stumbled on a man who was not averse to his secret being known. Vernon wondered what the ex-police-commissioner had done that he should have one at all, and looked forward eagerly to being told. Dimsdale was such a very respectable old gentleman, and so very open in his speech and actions and entire life, that it seemed incredible he should conceal anything. However, as The Spider had learned in some extraordinary way, he did possess some secret, and therefore was being threatened. It was lucky for Dimsdale in particular and the public at large that he cared so little for the revelation of whatever shady doings he had been concerned in, since by trapping The Spider an end would be put to the dangerous career of this social pest. Whatever Mr. Dimsdale's secret might be, he well deserved to be forgiven for the service which he was rendering to everyone.