Ross (Turner) must defend Cornwall from an empowered George Warleggan (Jack Farthing), and risks everything he holds dear as he embarks on a political journey which takes him to the nation's capital. Demelza (Tomlinson) finds her loyalties torn, Elizabeth (Heida Reed) tries to strengthen her marriage, Morwenna (Ellise Chappell) continues to be oppressed by husband Reverend Ossie Whitworth (Christian Brassington), and the Enyses (Luke Norris and Gabriella Wilde) are tested as never before.
