Did you know that this Ealing Studios film was based on a book? Published in 1907, Israel Rank by Roy Horniman is not really a funny book, although it does have a cruel humour at times. The film, however, is a black comedy in which Alec Guinness plays eight members of the aristocratic family. The concept of the story is that a man with a distant connection to the family (his name is Israel in the book, Louis Mazzini in the film) murders and marries his way to becoming a Lord. The story we are reading, or hearing, is his memoir written in prison while waiting execution.
There are some major differences between book and film. The most obvious, from the beginning, is that the protagonist is changed from being half-Jewish, to half-Italian, thereby avoiding some prejudices evidenced in the book, which predated the horrors of the 1930s and 40s. Another major difference is that his main method in the book is poison, while in the film he dispatches his relatives in a variety of ways and in such quick succession that it’s entertaining. He also persuades us that he’s doing the world a favour because his relatives are boring and snobbish. Throughout the story, he has an on-off relationship with Sibella, who regrets marrying the boorish Lionel. We get more insight into these characters in the book. The film has Louis working in a draper’s shop, emphasising his lowly status, before he enters the banking world.
The ending is rather different. In both the book and film, he gets a reprieve and leaves prison. In the book, he has made careless mistakes when murdering the Lord (the last relative in the way) but one of his lovers, Esther, sacrifices herself by confessing. So he gets away with it and has rather a nice life. In the film, he manages to inherit the manor, but is tried for the murder of Lionel. He is about to meet his fate, when a suicide note by Lionel is discovered (the work of Sibella). Louis leaves the prison and has to decide between Sibella, or his wife. We never know his decision, because he realises that his manuscript, describing the murders, is still in the prison. This suggests he won’t get away with it, which accords with the morality we expect from films in this era. I think the book is more radical in this respect, as we’re used to books now where crime goes unpunished, but it must have been unusual for the time. Still, I didn’t enjoy the book much (I found it on Project Gutenberg) and would rather watch the film.