A bookmakers clerk, Grierson, finds himself in financial difficulties and forces his step-daughter to marry Nevern, a caddish song-writer, for his money. When she finds life unbearable with Nevern she decides to divorce him and marry Hardwicke, a newspaper reporter. Grierson schemes to murder Nevern in the hope that his step-daughter will inherit all his money and that she'll be generous towards him (not knowing he will be the murderer). After secretly building up what he thinks is alibi upon alibi, he commits what he believes to be the perfect crime, only for an incredible slip to prove his undoing.