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.

A captain is promoted by his company from tramp steamers to their flagship passenger liner. Although he is a thoroughly competent sailor ready to take charge of such a ship, he is less prepared for the social duties his new position involves, not least the way he in which becomes the target for all the unattached women on board.