The Perfect Alibi

At Heron Court, where Mollie Cunningham lives with her guardian, the wealthy Arthur Hilton, guests enjoy the lake and sunshine of his country estate. One night at the dinner table, Hilton tells about his days in Africa, where he helped round up a gang of murderers. He explains that several of these criminals were set free based on a flaw in the evidence, but not before swearing vengeance against him. Later, Mollie and Hilton's nephew Jimmy confide to each other that neither one likes Laverick, a guest. The next day, Carter and Laverick stay at the house, while the other guests go to a flower show in town. Having work to do, Hilton is busy in his study when Carter enters and tells him that he suspects Laverick of being one of the murderers he captured in Africa. When they see Laverick coming, Carter decides to hide behind a curtain in the study so that he can overhear Laverick's reaction to Hilton's accusation. When Laverick pulls his gun on him, Hilton dials the police chief's house, and tells Carter to come out from hiding. Before Hilton can tell the police chief why he has called, Carter jumps out and shoots Hilton. Joe Mallet, the chief's son and a sergeant at Scotland Yard, receives the call and, suspecting foul play, goes to the flower show to get his father. Meanwhile, Carter changes the blotter on the desk and arranges the scene to look like a suicide. At the house, when Joe questions the guests, Laverick and Carter vouch for each another, and both claim to have noticed the time while they were outside the house. Later that night, all the guests retire except Jimmy and Mollie, who are convinced that Hilton was murdered. In the study, while they are discussing the facts, Mollie notices that the blotter has been changed. She and Jimmie then realize that Laverick and Carter could not both have noticed the time as they claimed. Just then, Mrs. Green, Carter's fiancée, enters the study in search of a pen and inadvertently informs the two that she has just seen Carter burning some paper. Carter realizes that Jimmy and Mollie suspect him and goes to Laverick to tell him that they must leave. The next morning, Mollie tells Carter that she suspects Laverick is the murderer, as she found the blotting paper in his possession. Jimmy, who is driving Laverick to the train station, stops and asks Joe to search Laverick's luggage for Mollie's missing jewelry, which they have previously planted on him. When he finds them, Joe suggests that they all return to the house to discuss the matter. Back at the house, Carter realizes that Mollie is on to him and pulls a gun on her. He discovers that she has locked them both in the room, and gives her to the count of ten to hand over the blotting paper. Meanwhile, Jane, Mollie's friend, has slipped into the room and overheard Carter's confession from behind the curtain. Mollie then informs Carter that his gun is not loaded. The police, who are listening just outside the door, enter and arrest Carter, and the young people finally breath a large sigh of relief.