A Case of Identity: Against the wishes of her stepfather, Mary Sutherland has become engaged to Hosmer Angel. On the morning of their wedding Hosmer elicits a promise that Mary will remain faithful to him "even if something quite unforeseen" occurs, then mysteriously disappears en route to the church. Holmes deduces that Hosmer was Mary's stepfather in disguise, the charade a bid to keep Mary a spinster and thus maintain access to her inheritance. Holmes does not reveal the truth to Mary because "There is danger for him who taketh the tiger cub, and danger also for whoso snatches a delusion from a woman"; he had already advised her to put the matter behind her, though she responded that Hosmer "shall find me ready when he comes back."
The Boscombe Valley Mystery: Inspector Lestrade asks for Holmes's help after Charles McCarthy is murdered, and his son, James, is implicated. McCarthy, and another local landowner, John Turner, are both Australian expatriates, and Lestrade was originally engaged by Turner's daughter, Alice, who believes James is innocent. Holmes interviews James, and then inspects the scene of the murder, deducing a third man was present. Realising Holmes has solved the case, Turner confesses to the crime, revealing that McCarthy was blackmailing him due to Turner's criminal past. Holmes does not reveal the crime, but secures James's release because of the presence of a third person at the crime scene.
