Three Scottish doctors, living comfortably in London, have been friends since their boyhoods in Edinburgh. Settling into middle age brings certain discontents, especially for Doctor Forrest, who is particularly conscious of his fading looks and the departure of his young and beautiful girlfriend. When he suddenly disappears, the police find nothing suspicious but his two friends are determined to solve the mystery. In doing so they become involved in a series of curious and disquieting events and uncover a surprising side to Doctor Forrest.