Louis Mazzini is shunned by his family, the rich, landed, and influential D'Ascoyne family, as a result of his mother's marriage to a poor, foreign commoner. Growing up without the trappings of wealth and privilege, the death of his mother makes Louis determined to inherit the family title - even if he has to murder his entire family in the process.
Dennis Price plays Louis Mazzini superbly in this darkest of black comedies. He's very straight-laced, english-gentleman, stiff-upper-lip in all of his murderous dealings. And although this movie is best remembered for the performances of Alec Guinness as the eight members of the D'Ascoyne family between Louis and the title of 10th Duke of Chalfont, it's really Dennis Price that steals the show every time.
Delivered as Louis writes his memoirs whilst waiting for his 8am appointment with the hangman, we see the life of this proud, down-trodden man as he struggles to claw his way to the top over the lives, and deaths, of those around him. People like his childhood sweetheart Sibella (Joan Greenwood) who I couldn't help but think of Fenella Fielding in Carry On Screaming when she spoke. People like his boyhood 'friend' Lionel (John Penrose) who goes and marries Sibella. This focuses Louis's mind on the task at hand - the systematic removal of his his relatives and the taking of his rightful place as Duke of Chalfont.
But we also know that he's writing from prison, and is due to be executed - so where does his plan come unstuck?