[1] Loosely based on the 1952 novel Mrs McGinty's Dead by Agatha Christie, it stars Margaret Rutherford as Miss Jane Marple, Ron Moody as the theatre company director H. Driffold Cosgood, Charles Tingwell as Inspector Craddock, and Stringer Davis (Rutherford's husband) as Mr Stringer.

[3] Margaret McGinty, a barmaid and former actress, is found hanged, and her lodger, Harold Taylor, caught at the scene, seems plainly guilty.

Cosgood is unimpressed by her acting ability, but as she mentions that she has independent means, he hopes for a financier and allows her to join the company without being paid.

With the help of Mr Stringer, Miss Marple investigates the staging history of that play and also Mrs McGinty's past connection to the company.

[5] The police station to which Miss Marple is taken for questioning by Inspector Craddock and Sergeant Brick, following the death of the actor George Rowton, is on Shady Lane in Watford, Hertfordshire.

The YMCA where Mr. Stringer stays and where Miss Marple meets him in the grounds to discuss her progress in the investigation – supposedly near the Palace Theatre where the Cosgood Players are performing, and their lodging house nearby – is actually Memorial Park in Pinner, in what is now the London Borough of Harrow.

Margaret Rutherford performs a section of the poem "The Shooting of Dan McGrew" by Robert W. Service in the film.