1790 and there is riot and revolution in the air. Ross Poldark (Aidan Turner) must fight for his freedom when George Warleggan (Jack Farthing) tries to have him hanged as a revolutionary. While Francis (Kyle Soller) and Elizabeth (Heida Reed) watch on in horror, can Demelza (Eleanor Tomlinson) save Ross from himself?

Crippled by debts, Ross and Francis try to heal old wounds by joining forces in a new mine free of the Warleggans. Ross and Elizabeth are thrown together by unforeseen circumstances, and Ross risks everything in a desperate smuggling venture. Meanwhile, the fate of the Poldarks is tied to Dr Dwight Enys (Luke Norris) and young heiress Caroline Penvenen (Gabriella Wilde) in unexpected ways.

The Poldark clan must learn to settle their differences once and for all, but at what cost?