The story concerns a young American geologist, Stanton Laird, working in the Australian outback in the field of oil exploration. Although he is in a very remote location - beyond the black stump - in a region called "the Lunatic" in Western Australia, he is part of a crew that has a well-appointed mobile facility.He is befriended by a local farming family, the Regans, and develops a relationship with their daughter Mollie. The Regans run an enormously profitable station, but their domestic lifestyle is, to say the least, unconventional, with the two Regan brothers at one time having Mollie's mother move from one to the other without bothering to get a divorce. The family is large, and even larger when counting the half-caste children produced by both fathers, and the children are taught by the Judge, an English exile and alcoholic, who gives the children an excellent education and keeps the finances of the station properly accounted for.