A member of British Intelligence assumes a fictitious criminal identity and allows himself to be caught, imprisoned, and freed in order to infiltrate a spy organization and expose a traitor; only, someone finds him out and exposes him to the gang...

In Dublin circa 1911, John Cassidy (Rod Taylor), an impoverished idealist, whose ambitions are restricted by the demands of looking after his family, journeys through the social injustices of Dublin life, involving himself with the rowdy tramway-men strike, dawdling with prostitute Daisy Battles (Julie Christie), and seeking a better life. He falls in love with bookshop assistant Nora (Dame Maggie Smith) who encourages him toward a life of writing. Finding success at the Abbey Theatre, his unorthodox views estrange him from family, friends, and his own past.

Short of money the owners of Ballyroden Hall must attempt to run it as a guest house, but not everyone is happy about the plan.

A family reduced to imminent poverty by the father's disinclination to work; an American lawyer looking for the heir to half a million pounds; the scene is set for a hilarious tale of creative deception!