Jabez Wilson is a pawnbroker. He explains his occupation and his unusual problem to Sherlock Holmes and Dr. Watson at Holmes' lodging in Baker Street.
"I have a small pawnbroker's business at Coburg Square, near the city. It's not a very large affair, and of late years it has not done more than just give me a living. I used to be able to keep two assistants, but now I only keep one; and I would have a job to pay him but that he is willing to come for half wages so as to learn the business."
A small pawnshop is an ideal setting for the mystery Doyle is creating because such an establishment would not have a steady flow of trade but only an occasional caller who wanted to pawn some trinket or one who wanted to redeem something. In such a shop, the doorbell would ring whenever a customer entered, so there would be no need for anyone to stay posted at the counter. This, as the cunning John Clay recognized, would give him plenty of time to go down into the basement and dig away at his tunnel, if only he could find a scheme to get his employer away from the premises for some time during the day.
Doyle does not describe the interior of the pawnshop, but he does capture the appearance and atmosphere of the quaint, sleepy old Saxe-Coburg Square where Wilson's struggling business is located.
"Let me see," said Holmes, standing at the corner and glancing along the line. "I should just like to remember the order of the houses here. It is a hobby of mine to have an exact knowledge of London. There is Mortimer's, the tobacconist, the little newspaper shop, the Coburg branch of the City and Suburban Bank, the Vegetarian Restaurant, and McFarlane's carriage-building depot."
One of the main attractions of the Sherlock Holmes stories is that they take the reader in imagination into many different parts of England, both the interiors and exteriors, and in city and country, opium dens and majestic manors, where every kind of man and woman is to be met. Jabez Wilson, the gullible pawnbroker with the flaming red hair, and John Clay, the aristocratic burglar who has connections to the infamous Dr. Moriarty, are just two such unique characters.