It is England, 1960. The mercurial and debonair Jack Whitaker and his intellectual wife Helen welcome a young German woman, Renate, into their off-balance household as an au pair to their two precocious daughters. The girls can’t wait to sink their teeth into this horn-rimmed, earnest foreigner. Neither, it seems, can their father. Cologne hangs on the cusp between post-war and swinging London as it documents the collision between war-torn history and the innocence of childhood.