A newspaper announces the murder of Mary Turner at her farm. Charlie Slatter, a neighboring farmer, arrives at the Turner farm shortly after the murder with the police sergeant; they find that Moses, the native houseboy, has given himself up as the murderer. Dick Turner, Mary's husband, has lost his sanity; and Tony Marston, a young man hired to take over Dick's farm for a few months, senses some unspoken terror among the Southern Rhodesian white men.
Mary Turner grows up in an impoverished family in Southern Rhodesia. She moves to the town and works well but is not able to associate well with other people, nor to marry. She decides to marry Dick Turner, a farmer, and leave the town to move to his farm.
Mary tries to acclimate herself to the rough life on the farm. She and Dick try making love, but Mary is put off by the experience. Dick feels guilty about this.
Mary notices that Dick speaks Kitchen Kaffir with the native house-servants and field workers. She tries to study the language herself so that she too may command the natives.
With too much time on her hands at home while Dick is working in the fields, Mary embroiders and tries to do the most she can with the house. However, she finds herself in constant tension with the native houseboys, whom she berates and treats so poorly that they keep quitting.
Dick gets the idea to try beekeeping to make more money, but this fails. More ideas similarly fail, much to Mary's exasperation. She escapes from the farm back to the town but is unable to take back her old job. Dick arrives and takes her back to the farm.
Dick contracts malaria and becomes bedridden for a time, during which Mary has to take over supervision of the fieldwork. She is harsh to the workers and even goes so far as to whip one in the face.
Mary convinces Dick to grow a larger tobacco crop to try to make a lot of money in one go, but a drought ruins their hopes. Dick brings in Moses, the worker whom Mary whipped, to work as the houseboy, much to Mary's distress.
Having lost faith in the farm, Mary becomes lethargic and finds herself falling under the power of Moses, who looks after her when she is in a weakened state.
Charlie Slatter, a neighboring farmer, pays the Turners a visit to try to convince Dick to see him his farm. Though his original motivation was to make more money, upon noticing the strange relationship Mary has with Moses, he practically compels Dick to leave his farm for a time. Charlie sets up Tony Marston, a young man fresh from Britain, to watch over the farm.
Knowing little about life outside of farming, Dick loses his will to live as the time for departure nears. Tony, who has started living on the farm, stumbles upon Moses dressing Mary and demands that Moses leave. Moses leaves but then returns and kills Mary, who has, in a dream-like state, wandered out of the house at night to meet him.