Killing Heat - Digitally Remastered. Killing Heat is a 1981 drama film based on Doris Lessings 1950 novel The Grass Is Singing. It stars Karen Black and John Thaw and was filmed in Zambia. Taking place in Southern Rhodesia in the 1940s, Killing Heat is the story of Mary (Karen Black), a city woman who marries a farmer named Dick Turner (John Thaw). Mary is pulled from the comforts of her cosmopolitan life and forced to live on Dicks unsuccessful farm. Mary slowly becomes insane and has a sexual affair with her black servant, Moses. When Mary and Moses affair is discovered Mary asks Moses to leave the farm. Moses returns and murders Mary. The film ambitiously tackles issues of colonialism, race and gender in this serious dramatic portrait of African colonial life.