In 1939 England, the Cuthbertsons - Helena (Felicity Kendal) and Richard (Paul Eddington), a war cripple - live in Cornwall with their orphaned niece, Sophy. Sophy is resented by Helena, and has little in common with Richard, and so is pleased when her four cousins arrive in August for a holiday. They talk excitedly about the possibility of war, and look forward to the 'Terror Run' - a night-time spree along a cliff path. Austrian refugees Max and Monika Erstweiler are invited to the traditional family dinner which takes place before the run, but the evening comes to an abrupt end when the news arrives that the outbreak of war is imminent.