There is virtually no part of this plot which has not been used better elsewhere.The basic premise of murders being carried out backstage at a theatre had been in constant use since the coming of sound.So the real shock comes when you see an ageing Frances Day at the beginning of the film.She was only in her early forties but looks much older.Apparently she was known as the Marilyn Monroe of the thirties.She had affairs with 4 royal princes,Anthony Eden and some well known female film stars.It is little surprise that she does not survive till the end of this rather moth eaten film.After all characters being murdered to try and preserve a secret is the basic premise of Gaslight.The pairing of John Bentley and Patricia Dainton fails to breath life into this film.