The Mark of Cain

English industrialist Richard Howard (Eric Portman) visits Bordeaux to buy cotton for his mills from Sarah Bonheur (Sally Gray) He becomes enamoured by Sarah and spends much of his business trip sight-seeing. When living a lonely existence in John's grand house in Manchester, England, Sarah confides to Richard that she is depressed by her marriage. Richard encourages her to divorce John and run off with him. Seeking revenge, Richard poisons his brother and attempts to frame Sarah for the murder.