Dr. Watson drops in on his friend Sherlock Holmes to find him in conversation with a man with fiery red hair, a Mr. Jabez Wilson. Wilson has come to Holmes with a problem concerning an organization for which he was working but that has mysteriously disappeared. Wilson owns a pawnshop but had for the last two months been employed part-time. At Holmes' urging, he tells his story.

Wilson's assistant Vincent Spaulding had pointed out to Wilson a job notice in the newspaper. It was a job sponsored by the Red-Headed League, and only men with red hair need apply. Spaulding convinced Wilson to go to the interview, and because of the bright color of his hair, Wilson was hired. His job was to copy the Encyclopaedia Bri-tannica from 10 A.M. until 2 P.M. He was not to leave the room at all, or he would lose...