The Missionary (1982) on Netflix

Plot summary

Charles Fortescue has spent a decade as a missionary in Africa. Back in England, he is engaged to Deborah Fitzbanks, a clergyman's daughter. She was a child when he left and now wants marriage and a large family. The Bishop of London hands him a mission to the women of the evening around the London Docklands, but there is no money for it. Deborah writes to Lord Ames, England's richest man, for support. Charles calls at the Ames mansion, where the butler Slatterthwaite loses his way among the many rooms. Lord Ames dislikes missionaries; his wife, Lady Isabel Ames, is willing to contribute, and tells Charles she finds him attractive. Alarmed, he tries to leave, but she insists that he stay the night.