Build a movie plot around this: What is William Marble's profession? Foreign exchange agent
Answer:
As Hammond shows a prospective tenant a house in London, the two men discuss the murder that was committed by its former occupant, Willie Marble, and wonder what the walls would say if only they could talk: The Marbles are overwhelmed by debts, and Willie will lose his job in the foreign exchange department of a bank if he doesn't settle a suit brought against him. He hears about a potentially lucrative speculation in the French franc, but hasn't the money to invest in it. When his nephew, James Medland, suddenly arrives from Australia, Willie hopes that the young man's obvious wealth will help him, but James is neither interested in investments nor in giving Willie a loan. Willie then laces James's drink with cyanide that he keeps for his photographic hobby, and steals the money from James's wallet. After burying the body in the backyard, Willie is haunted by it and even his making 30,000 on the franc speculation does not calm him. He sends his wife Annie and daughter Winnie on a holiday and stays home, reading about poisons. He begins an affair Mme. Rita Collins, who owns a local dress shop, but stops when Winnie finds out as she and her mother return a day early from their holiday. Annie soon realizes what Willie has done. Rather than turning him in, her understanding seems to ease Willie's conscience. Their life is peaceful for a while, but when Winnie tells her mother about Willie's affair and decides to stay with some upper-class friends instead of remaining at home, Annie rushes after her in a storm and becomes very ill. One day, Rita comes to the door and demands that Willie pay her five hundred pounds. Willie wants her to leave, but their voices are heard by Annie, who sneaks downstairs. Seeing Willie give Rita the money, Annie assumes that their affair is still going on and decides to kill herself. She then puts poison in her glass of orange juice and becomes gravely ill. When she dies, the doctor discovers that she has been poisoned and assumes that Willie has murdered her. Willie is then...