Retired archaeologist Judith Potts lives alone in a faded mansion in the peaceful town of Marlow, filling her time by setting crosswords for the local paper. During one of her regular wild swims in the Thames, Judith hears a gunshot coming from a neighbour's garden and believes a brutal murder has taken place.

Ex-cop Jim Bergerac is forced to confront a troubling past case when a wealthy woman is murdered, pushing him to overcome personal demons and reignite his investigative prowess to navigate family tensions and law enforcement scrutiny.

Based on the story of the Mitford sisters, six sisters who refused to play by the rules and whose often-scandalous lives made headlines around the world. Set in the 1930s, it is a tale of betrayal, scandal, heartache and even imprisonment.