The story begins with a visit to 221B Baker Street from Steve Dixie, a black man and a cowardly ruffian who warns Sherlock Holmes to keep away from Harrow. Although Dixie has come to intimidate Holmes, Holmes secures Dixie's future cooperation by threatening to tell what he knows about the suspicious Perkins death involving Dixie. Dixie's boss is Barney Stockdale, and he must be connected with the Harrow Weald case, of which Holmes has just learnt from a message from Mary Maberley, a lady who lives at Three Gables, a house at Harrow Weald.