Black Bag on AllMovie

This mystery is based on the novel by Louis Joseph Vance. While on vacation, Billy Kirkwood (Herbert Rawlinson) meets pretty Dorothy Calender (Virginia Valli) when she dashes alone into the restaurant where he is dining. Dorothy, who is in possession of a valuable necklace, is trying to avoid a strange man who seems to be pursuing her. Kirkwood attends a summer resort on Long Island so he can continue to see Dorothy, but he is told she is a crook. When he finds the necklace in Dorothy's room he really believes that she is a thief and steals it himself so that he can return it to the jewelry store. When Dorothy finds the necklace missing, she assumes that Kirkwood is a burglar and sets the police after him. Only after they take him in does the whole truth come out -- the strange man who was following Dorothy is the thief. The necklace is hers -- she got it from her uncle's jewelry shop. Incidentally, it was quite obvious to those who were familiar with Long Island that this picture was filmed in California.