When Mr. Rucastle finds out that his daughter Alice is engaged to be married, he becomes furious because he knows that control of the family fortune will shift to her under the provisions of his late wife's will. He orders the fiancé out, and when Alice refuses to sign away control of the estate, he locks her in a shed. He intercepts a note from the fiancé arranging a rendezvous near the copper beech trees on the estate. Rucastle hires Violet Hunter as governess to his six year old son. Violet resembles Alice enough that he hopes to convince the fiancé that she is still in the manor house. After he cuts Violet's hair, the suspicious governess enlists Holmes' aid. The great detective uncovers the plot, frees Alice, and has the scheming Rucastle arrested.