Horace Dorrington was considered one of 'The Rivals Of Sherlock Holmes' in Toobworld, whose exploits were first chronicled in a series of stories by Arthur Morrison. As a private investigator, he was corrupt, amoral, and on at least one occasion, a murderer. He could be relied upon to solve his cases, if only that, but always as a means to lining his pockets with more than his established fee with the client.
Wold Newton scholar Rick Lai considers Dorrington to have been the third most dangerous man in London, after Professor Moriarty and Colonel Moran from the Sherlock Holmes canon.
In one of his cases (set in 1895 as per the TV series, if not the original stories), Dorrington was hired to retrieve the fabled Mirror of Portugal, a diamond thought lost since the French Revolution. Until recently it was passed down through the generations of his client but it was stolen from around his neck. Dorrington tracked down the thief to be a Mr. Hamer, who shared an office with the client.
Dorrington forced Hamer and his wife to take him to where the diamond was kept, but it turned out Mrs. Hamer had it on her all the time. And when they reached the Thames, she threw the legendary stone into the river - if she couldn't have it, then no one would. After first insuring that he had collected his fee from his client, he then told the man and his brother where it could be found... which is all that he had been contracted to do.
It wasn't just water that flowed down into that shaftway, but the muck and the mire and all the detritus to be found in the Thames. And that included the Mirror of Portugal.....