Distant cousins and childhood friends Elinor Carlisle and Roddy Welman are happily engaged to be married. One day Elinor receives an anonymous letter in the post, claiming that someone is trying their hardest to work their way into the affection, and subsequently also bank account, of her wealthy aunt Laura Welman, who is presently bedridden at her home since after a stroke and from whose death Elinor and Roddy both expect to inherit a large fortune. Not knowing what to make of the letter, the young couple eventually decide to pay Laura a visit in order to see for themselves what is really going on at the house. When they arrive, Elinor immediately becomes suspicious towards Mary Gerrard, the lodge keeper's daughter, recently returned to England after having studied in Europe and whom everyone else at the house seem to absolutely dote on. No one else however seem to share Elinor's suspicions or dislike of the young woman...