Enter Sir John is a 1928 British crime novel by Clemence Dane

Clemence Dane

Clemence Dane was the pseudonym of Winifred Ashton , an English novelist and playwright.-Life and career:...

 and Helen Simpson

Helen de Guerry Simpson

Helen de Guerry Simpson was an Australian novelist.-Life and career:Simpson was born in Sydney into a family that had been settled in New South Wales for over 100 years...

. It concerns Martella Baring, a young actress, who is put on trial and convicted of murder and a fellow actor Sir John Saumarez who takes up her cause and tries to prove her innocence. It was followed by a sequel Re-enter Sir John

Re-enter Sir John

Re-enter Sir John is a 1932 British crime novel written by Clemence Dane and Helen Simpson. It was the sequel to the 1928 novel Enter Sir John, which had been adapted into a film Murder! by Alfred Hitchcock. The story continued the adventures of the actor-manager Sir John Saumerez.-Bibliography:*...

in 1932.

Film adaptations

In 1930 the play was adapted into a film Murder!

Murder!

Murder! is a 1930 British drama film directed by Alfred Hitchcock and starring Herbert Marshall, Norah Baring and Edward Chapman. It is based on a novel and play called Enter Sir John by Clemence Dane and Helen Simpson...

and a German-language version Mary both of which were directed by Alfred Hitchcock

Alfred Hitchcock

Sir Alfred Joseph Hitchcock, KBE was a British film director and producer. He pioneered many techniques in the suspense and psychological thriller genres. After a successful career in British cinema in both silent films and early talkies, Hitchcock moved to Hollywood...

. A number of changes were made from novel to screen such as making Sir John a member of the jury while in the book he was just a specator at the trial. The story was also adapted into a play.