Diana Baring (Norah Baring), a young actress in a travelling theatre troupe, is found in a daze with blood on her clothes, sitting by the murdered body of another young actress, Edna Druce. The poker used to commit the murder is at Diana's feet, but she has no memory of what happened during the minutes the crime was committed. The two young women are thought to have been rivals, and the police arrest her. Diana withholds some important information deliberately, to protect something about the identity of a man that she will not name.
At her trial most of the jury are certain she is guilty. One or two feel that she may have a severe mental illness which means that she really does have no memory of killing the other woman, but they are convinced that she should still be hanged lest she strike again. One juror, Sir John Menier (Herbert Marshall), a celebrated actor-manager, seems sure she must be innocent, but is brow-beaten into voting "guilty" along with the rest of the jury. Diana is imprisoned, and awaits hanging.
Sir John feels responsible, as he had recommended that Diana take the touring job in order for her to get more experience. He discovers Diana has been a fan of his since childhood. She is beautiful, and seems far too honest and straightforward to be a criminal of any kind. Using skills he has learned in the theatre, Sir John investigates the murder with the help of the stage manager Ted Markham (Edward Chapman) and his wife Doucie (Phyllis Konstam). They narrow the possible suspects down to one male actor in the troupe, Handel Fane (Esme Percy).
During a prison visit with Baring, Sir John learns Fane's secret: he is a half-caste, only passing as white, and Druce had threatened to expose him. Sir John cunningly tries to lure a confession out of Fane, by asking him to audition for a new play that Sir John has been writing. Sir John describes a plot closely resembling the murder, and Fane realises that they know he committed the crime, and that they understand how and why he did it. Fane leaves the audition without confessing, and goes back to his old job as a solo trapeze performer in a circus. Sir John and the others go there to confront him again. During his performance, he looks down from his high perch and sees them waiting. Despairing, he knots his access rope into a noose, slips it over his head and jumps to his death. Sir John and Markham discover Fane had written a confession to the murder before his suicide.
At the film's conclusion, Diana is shown free, and gloriously dressed in white furs, entering a beautiful room and being welcomed warmly by Sir John, who receives her as if he loves her. The camera pulls back and reveals this is the last scene of a new play, possibly the new play, in which Diana stars opposite Sir John. They kiss as the curtain falls.
Alfred Hitchcock as man, with a female companion, walking along the street, while Edward Chapman is speaking to Herbert Marshall and Phyllis Konstam [uncredited]
The film was made by British International Pictures. It was originally to be released under the same title as the novel, Enter Sir John, but this was changed to the simpler Murder! during shooting.[2] A number of changes were made from the book, including altering the names of the two principal characters. The portrayal of the character Sir John Mernier was loosely based on that of the actor Gerald du Maurier, who was a friend of Hitchcock.[3] Hitchcock later adapted three novels written by du Maurier's daughter Daphne du Maurier: Jamaica Inn (1939), Rebecca (1940) and The Birds (1963). Hitchcock makes his cameo appearance in the film as a man walking past the murder victim's house.[3]
The German language version of the film, Mary (1931), was shot simultaneously on the same set with German-speaking actors. Miles Mander reprised his role as Gordon Druce in Mary, though the character's name was changed to Gordon Moore.[4]
For the filming, an orchestra played the music live on the set. Hitchcock described the filming of this scene to François Truffaut in the book-length interview Hitchcock/Truffaut (New York: Simon & Schuster, 1967). In the early days of sound film, there was no way to post-dub sound, so Hitchcock had Herbert Marshall's voice recorded on a phonograph record, which was played back during the filming of the scene, while the orchestra played the "radio" music live.
