Mr. Watson goes to visit his friend, a private detective Mr. Holmes at his home. There he finds Mr. Holmes talking to Mr. Wilson, owner of a pawn shop to help him to solve a mystery. One day Wilson's assistant Vincent Spaulding shows an advertisement stating to hire red-haired men. On Spaulding persuasion, Wilson goes for the interview and gets selected for the job by Mr. Duncan Ross. They promised to pay Wilson four pounds per week and have to work four hours per day from \(10.00\) am to \(2.00\) pm for rewriting the Encyclopedia Britannica in longhand. One day Wilson looks at the notice saying the league is closed. Wilson wanted to find the reason behind it.
Sherlock Holmes promised Wilson to solve the mystery. He and his friend go near the Wilson's shop at the Saxe-Cobourg square, and Holmes taps here and there in front of the shop and sometime later knocks the door. Spaulding opens the door with dirty pants, which Holmes notices clearly. Later Holmes goes behind the shop and finds a bank there, and everything becomes clear to him that Spaulding used the Red-headed league by the help of Ross his accomplice to keep Wilson away from the shop to dig the tunnel from the shop to the bank for robbery. Finally, Holmes made a plot along with his friend Wilson, a policeman, and a detective named Jones to catch the thieves.