The Locked Door is a 1929 drama film featuring Barbara Stanwyck in her second film appearance, first starring role, and first talking picture. It was based on the play The Sign on the Door by Channing Pollock.
Ann Carter (Barbara Stanwyck), an inexperienced young woman, accepts an invitation to dinner from Frank Devereaux (Rod LaRocque), the son of her employer. The date turns out to be far from what she expects. It is aboard a "rum boat", a ship that sails beyond the 12 mile limit to get around the restrictions of Prohibition. Worse, Frank turns out to be a cad, she tries to leave, but he locks the door and tries to force himself on her, tearing her dress. Fortunately, the ship drifts back into U.S. waters and a police raid stops him from going any further. When a photographer takes a picture of the two under arrest, Frank buys it from him.
Eighteen months later, Ann is happily married to wealthy Lawrence Reagan (William "Stage" Boyd). They are about to celebrate their first wedding anniversary when Frank resurfaces in Ann's life, this time as the boyfriend of her naive young sister-in-law, Nancy (Betty Bronson). Though both Ann and her husband tell Nancy that Frank is no good (Lawrence knows that Frank is having an affair with the wife of one of his friends), it is clear to Ann that Nancy does not believe them.