Anthony Asquith's film adapted from Terence Rattigan's play is based on real events that took place in 1912. When young Ronnie Winslow is expelled from Naval College after being accused of stealing a postal order, his banker-father remains convinced of his innocence and risks everything to press for a retrial with the assistance of a high-profile barrister. By doing so, the trial becomes a cause célèbre and the family's social standing becomes precarious.