The story of events surrounding the notorious divorce of the Duke and Duchess of Argyll during the 1960s.
Cast: Claire Foy, Paul Bettany, Olwen May, Albertine Kotting McMillan, Julia Davis, Richard McCabe, Amanda Drew, Phoebe Nicholls, David Monteath, Richard Goulding, Mitchell Robertson, Sophia Myles, Don Gallagher, Camilla Rutherford, Sophie Ward, Daniel Burt, Timothy Renouf, Miles Jupp
Battlelines are drawn as the Duke and Duchess of Argyll enter into a bloody separation, all played out in the white-hot glare of a ravenous press.
Putting aside gnawing doubts about her marriage, Margaret continues with her plan to secure her claim to Inveraray Castle.
Considered the most beautiful debutante of the 1930s, heiress Margaret Sweeny (Claire Foy) is in the midst of a divorce when she meets the dashing - and married - Ian Campbell, future Duke of Argyll (Paul Bettany).