Mary Sutherland, who possesses a substantial income from the interest on a fund set up for her, comes to Sherlock Holmes and Dr. Watson for help after her fiancé, Hosmer Angel, disappeared on their wedding day. Taking the case, Holmes discovers Sutherland knew little of Angel; only that he is a quiet and secretive Londoner who works at a Leadenhall Street office, communicated to her through typewritten letters, insisted that she write back via the local post office, and only met with her whenever her young disapproving stepfather and trustee of her inheritance, James Windibank, claimed he was out of the country on business.