Anthony Hancock gives up his office job to become an abstract artist. He has a lot of enthusiasm, but little talent, and critics scorn his work. Nevertheless, he impresses an emerging very talented artist. Hancock proceeds to con the art world into thinking he is a genius.

New inmate Rainbow has just been imprisoned for a year for his part in a fight over his girlfriend Wendy. After being assigned to kitchen duty, he becomes involved in a food-trading racket. When the scheme is betrayed to the prison's governor, its prime mover is threatened with an extended sentence - unless Rainbow can come up with a way to save him.

1958 film by Anthony Asquith