In "The Red-Headed League," what do Mr. Jones and Mr. Merryweather each stand to gain from the capture of John Clay?
In "The Red-Headed League," Mr. Jones the police agent and Mr. Merryweather the bank director are minor characters brought in at the climax. Mr. Merryweather does not realize how much he stands to gain and has come to the branch bank only because of the assurance of Jones, to whom he says:
"Oh, if you say so, Mr. Jones, it is all right. . . . Still, I confess that I miss my rubber [of bridge]. It is the first Saturday night for seven-and-twenty years that I have not had my rubber."
Merryweather will soon learn that Holmes is saving his bank from the loss of 30,000 gold napoleon coins from the Bank of France. No doubt the bank director will claim part of the credit for saving his firm from a catastrophic loss.
As far as Jones is concerned, he is eager to capture the infamous John Clay. As he tells Merryweather:
"John Clay, the murderer, thief, smasher, and forger. He's a young man, Mr. Merryweather, but he is at the head of his profession, and I would rather have my bracelets on him than on any criminal in London."
By capturing John Clay, Jones would be taking a dangerous criminal out of circulation and undoubtedly receiving praise and promotion at Scotland Yard. Jones will get a great deal of the credit for the capture of Clay, although he knows virtually nothing about how Sherlock Holmes came to understand what an audacious crime was about to be perpetrated.
Arthur Conan Doyle acknowledged his indebtedness to Edgar Allan Poe, who is credited with inventing the detective story with two tales featuring Auguste Dupin, an amateur detective. The tales were "The Murders in the Rue Morgue" and "The Purloined Letter." One of the conventions that Poe established, and Doyle copied, was the amateur detective's practice of letting the police take credit for the majority of his solutions. This enables Holmes, as it did Dupin, to obtain the cooperation of the police any time he requests it. Scotland Yard detectives, notably Inspector Lestrade, often come to Holmes for advice when they are stymied in their investigations, and this is one of the ways in which Holmes becomes involved in some of his most interesting cases.
When John Clay starts to climb into the bank vault and realizes he is trapped, he calls to his partner in the tunnel below him:
"Great Scott! Jump, Archie, jump, and I'll swing for it."
"To swing" is criminal slang for hanging--and Clay, with his long criminal record, as well as being caught red-handed in a bank vault full of French gold, is certain to be hanged in fairly short order.