Summary
Violet Hunter, a governess, comes to Holmes to tell him her misgivings about a job she is about to take. Although it is highly lucrative, she senses something off about Jephro Rucastle, her future employer. Some time after starting at The Copper Beeches, Hunter telegrams Holmes asking for his help. She explains that Rucastle has made her cut her hair and sit in a blue dress with the back of her head to a window for some time each day.
One day, with a hidden mirror, she discerns a man on the road by the house looking at her. When Mr. Rucastle and his wife notice this, they begin to abuse her. One night, Hunter tries to go into a room and is threatened by Mr. Rucastle, who says he will feed her to the family's mastiff.
Holmes reasons that Mr. Rucastle has imprisoned his daughter Alice Rucastle in that room; and so he and Watson sneak into the house to try to free her. However, Mr. Rucastle has already taken his daughter away. When he runs away from a confrontation with them, he inadvertently runs into the hound, who grievously mauls him.
Holmes hears the full story from Mrs. Toller, one of the house maids. Mr. Rucastle, in order to hold onto Alice's inheritance from her late mother, had tried to prevent her from marrying Mr. Foster, a man she loved. With the case solved, Alice is able to marry.
Analysis
One of the particular deductive skills that Holmes displays and explains in this case is the estimation of a suspect's personality by that of their child. While explaining this method of reasoning, Holmes refers to Watson's medical profession; we can understand this to mean that Holmes is up to date with the most current medical and psychological theories, insofar as they may be of use to his detective work. More so, or at least more explicitly than in other cases, Holmes finds it important to form a psychological profile of the suspect both in order to ascertain guilt and to form a plan of action.
