Having qualified as an accountant in a German prisoner-of-war camp, Joe Lampton leaves working-class, industrial Dufton behind him and takes a job as senior audit clerk at the town hall in affluent Warley. Having secured lodgings at "T'top" – the poshest part of the town – he starts to make his mark on Warley society. Good at his job, Joe quickly shows his natural skill at climbing the career ladder up through the petty politics of local government. But he has two things on his mind – money and sex – and his ambitions go well beyond anything offered by civic life.

He embarks on a plan to marry into the prosperous middle classes by joining the local amateur dramatic society so as to meet a better class of woman. Seeing that Joe's working-class, chip-on-the-shoulder attitude is likely to get him into trouble, fellow thespian Alice Aisgill takes him under her wing. She is 10 years older than Joe, and urges him to date Susan Brown, daughter of the richest and most powerful man in Warley.

Alice is unhappily married to a rich local car dealer and is known in the am-dram society as something of a femme fatale. She watches as Joe succeeds in luring Susan away from her rich boyfriend, Jack Wales. But Joe's cold-blooded ambition and Alice's detached role as matchmaker are blown apart by something neither she nor Joe can control – their passion for each other.