1950. The matriarch of the Cazalet family, the beloved Duchy, passes away, closing the door behind her to the world of estates and servants, class differences and unbreakable traditions in which the Cazalets flourished. Louise, now divorced, falls in love, but her romance turns out to be not so rosy. Polly and Clary, meanwhile, try to find a balance between family and their own ambitions. Hugh and Edward, both over sixty, feel lost in their new world. Willie, who has long been left by her husband, must finally learn to be independent. But the main tests await Rachel, who has always lived for others... The climax awaits the whole family in Home Place, where on Christmas a new generation of Cazalets will boldly come into their own. Only one thing is certain - life will never be the same again.