It is based on the popular West End stage comedy by Terrence Rattigan. It all begins when Diana (Ellen Drew), the sister of a British boy studying in France, arrives in town to flirt with all of her brothers' schoolmates. Alan (Ray Milland), one of the students, successfully resists Diana's charms-meaning of course that Alan and Diana will be in each other's arms by fadeout time. (AllMovie)

In the last days of Czarist Russia, Russian-speaking Briton A.J. Fothergill is enlisted by his government to go undercover as Bolshevik radical Peter Ouranoff in an attempt to gain access to the revolutionaries' inner circle. Tasked with accompanying lovely aristocrat Alexandra Vladinoff from Moscow to Petrograd to be tried for crimes against the proletariat, Peter attempts to spirit her out of the war-torn country.