Paul Pennyfeather (Robin Phillips) is a naive young divinity student at Oxford who finds himself sent down after a group of drunken undergraduates remove his trousers and he is accused of exposing himself.
Forced to look for work, he seeks the services of an unsavoury employment agency who secure him a position at Llanabba Castle – a sleazy boys’ boarding school in Wales presided over by the colourful Dr Augustus Fagan (Donald Wolfit).
The school’s staff are an assortment of eccentric characters: Mr Prendergast (Robert Harris) is a withdrawn former clergyman; Captain Grimes (Leo McKern) is a one-legged philanderer, pederast, bigamist and drunk with his eye on Fagan’s daughter; and Solomon Philbrick (Colin Blakely) is actually an undercover criminal posing as Fagan’s butler.
Paul meets Margot Beste-Chetwynde (Genevieve Page) – the enchanting and manipulative mother of one of his pupils who has her Rolls Royce painted in a succession of different colours to match her gowns – and the pair are set to be married until Paul is arrested for involvement in Margot’s white slavery operation.
Pennyfeather is convicted and sentenced to seven years in prison – where he meets several individuals who had also been academic colleagues at Llanabba Castle – but is released after a relatively short time with the help of Margot’s new husband, the British Home Secretary Sir Humphrey Maltravers (Griffith Jones).
The film is an adaptation of the 1928 novel Decline and Fall by Evelyn Waugh.
Paul Pennyfeather
Robin Phillips
Judge
Felix Aylmer
Solomon Philbrick
Colin Blakely
Prendergast
Robert Harris
Maniac
Patrick Magee
Captain Grimes
Leo McKern
Margot Beste-Chetwynde
Geneviève Page
Chief Warder
Paul Rogers
Prison Governor
Donald Sinden
Dr Augustus Fagan
Donald Wolfit
Sir Humphrey Maltravers
Griffith Jones
Arthur Potts
Rodney Bewes
Flossie Fagan
Patience Collier
Otto Silenus
Roland Curram
Mr Church
Kenneth Griffith
Director
John Krish