Two warring shop workers in a leather-goods store turn out to be secret sweethearts as they correspond under box-number aliases. Within this simple idea and an everyday setting, Lubitsch produces a rich tapestry of wit, drama, poignancy and irony that never lets up. Stewart and Sullavan are perfect as the average couple with real emotions and tensions, and the rest of the well-developed characters have their own sub-plots and in-jokes. Although wrongly eclipsed by Stewart's big films of 39/40 (Destry, Philadelphia Story, Mr Smith) this is easily on a par and we enjoy a whole range of acting subtlties unseen in the other films.