Summary
Mary Sutherland, a young woman, visits Holmes to ask for help with finding out what has happened to Hosmer Angel, a man she had fallen in love with and was just about to marry when he disappeared. She explains that she lives with her mother and step-father, James Windibank, the three of them living comfortably on money from her late father. From the fact that the letter Mary received from Hosmer Angel was typewritten and other suspicious clues, Holmes deduces the truth behind the mystery.
He invites Mr. Windibank over for an interview and reveals that he knows that the latter had in fact impersonated Hosmer Angel in order to prevent his daughter from marrying. He had hopped out from the carriage in which he was riding to be married with Mary and so effected a disappearance that would have resulted, with the promise he (as Hosmer) extracted from Mary to never marry anyone else, in Mary's never entering into marriage and thus never depriving him of the family money.
Analysis
As in several other stories, the primary motivation behind the crime in "A Case of Identity" is a man's desire to control a woman in order to remain in possession of her money, a logic that reveals the tight connection behind financial matters and sexual politics in Victorian England. When a woman falls in love and decides to marry, the proceedings necessarily have a large impact on the apportioning of money in her family.
This story also contains a scene of confrontation with the criminal that is remarkable for the highly moral stance that Holmes takes. Speaking to Windibank, Holmes even goes so far as to threaten extralegal violence, something that he never does before or after:
"'The law cannot, as you say, touch you,' said Holmes… 'yet there was never a man who deserved punishment more. If the young lady has a brother or a friend, he ought to lay a whip across your shoulders… it is not part of my duties to my client, but here's a hunting crop handy, and I think I shall just treat myself to—" (74).
Implicit in this speech are to notions worth remarking upon; namely, that a male relation ought to avenge the wrongdoing, and that although such an assault would not be sanctioned by the law, it would be socially accepted.
