Set in London, the film tells the story of a middle-aged Jewish doctor, Daniel Hirsh (Peter Finch), and a divorced woman in her mid-30s, Alex Greville (Glenda Jackson), who are both involved in an open love triangle with sculptor Bob Elkin (Murray Head), a younger man in his mid-20s. Not only are Hirsh and Greville both aware that Elkin is seeing the other but they know one another through common friends. Despite this, they are willing to put up with the situation through fear of losing Elkin, who switches freely between them.