Undertow is a 1949 thriller film directed by William Castle, starring Scott Brady, Peggy Dow, Bruce Bennett, Dorothy Hart and John Russell. It is the story of an excon, a former Chicago mobster, who is accused of the murder of a high ranking Chicago boss. The movie marks the second film to feature a young actor named Rock Hudson and the first in which he received a film credit for his work.
On his way home to Chicago, Reagan shares the flight with a schoolteacher, Ann McKnight Peggy Dow, someone he met at a Reno casino and helped win at the gambling table. Reagan arrives home and is met by the police. It seems that Reagan is a suspect as a potential trouble maker due to his past dispute with a Chicago mob kingpin, Big Jim, his fiancees uncle. The police put a tail on him, which he shakes on a Chicago elevated train. Reagan meets up with his bridetobe, Sally Lee Dorothy Hart. He tells her he will go to Big Jim to make peace. But when the uncle is murdered, Reagan is framed for the murder.On the run from both the police and from the unknown murderers, Reagan enlists the help of McKnight and an old buddy, Charles Recklilng Bruce Bennett, a detective. They discover the truth Morgan is also engaged to Sally Lee, and together they are responsible for murdering her uncle and framing Reagan. ........
Source: Wikipedia