Ward X [the setting for "An Indecent Obsession"] has reached a certain balance with the help of a nurse-catalyst, Sister Honour Langtry, who initially emerges as almost a stock character in British fiction—a combination of Jean Brodie and Mary Poppins. Into this stabilized environment comes a new element: a soldier named Michael who has been placed on Ward X for no discernible reason….

The environment is one of the chief villains in this novel. Half the action is concerned with warding off the elements and the pests that inhabit the hospital: keeping dry, keeping cool, keeping free of mildew, keeping flies and mosquitoes and roaches out. Everyone on the ward is obsessed with this. The heat and humidity are pervasive and oppressive, and in Mrs. McCullough's hands are a constant reminder of the claustral feeling of the hospital itself and of the souls imprisoned there. (p. 14)

Thematically...