Just before the outbreak of World War I, Edith Graydon married her boyfriend Percy Thomson. He survives the war but theirs is not a happy marriage. She doesn't really love him and he feels it every day. He's also possessive and their daily life is a constant battle. She meets and falls in love with Frederick Bywaters, her sister's one-time boyfriend. They have a long affair and her desperate attempts to get either a formal separation or divorce from her husband falls on deaf ears. They are at their wit's end and Bywaters decides to do something about it. On a dark evening when Edith is walking with her husband, Bywaters stabs him to death. Edith is charged with murder along with Bywaters and both are found guilty. She claims her innocence right up until the day they are both executed by hanging in 1923. Based on a true story.