The novel is one of the theatrical ones for which Marsh was best known, and concerns the murder of an actor backstage on opening night of a new play in London.

Martyn Tarne, a young and inexperienced actress from New Zealand, finds herself involved in a play where her own heredity plays a significant role in a minor part.

As the understudy for a minor role, Martyn is caught up when Inspector Roderick Alleyn begins investigating a murder made to appear a suicide.

A child witness in A Surfeit of Lampreys (American title Death of a Peer), he was a civilian eager to join the police force in "I Can Find My Way Out", and he appears in Opening Night as a police constable attached to the CID.

Opening Night was one of four Alleyn novels adapted for South Pacific Television in 1977[1] as Ngaio Marsh Theatre; Alleyn was played by George Baker.