In Cornwall, 1783, Ross Poldark returns from the battlefield to find his father dead, his estate in ruins, and his sweetheart Elizabeth engaged to his cousin.

Ross, having repaired Nampara, now sets his sights on resurrecting his family mine to bring prosperity to the area. Verity makes an unsuitable match and Elizabeth sets tongues wagging.

Ross celebrates the opening of Wheal Leisure, as rumours spread of a scandalous relationship between him and Demelza.

News of Ross and Demelza's marriage spreads through the community, damaging Wheal Leisure's prospects. Demelza is filled with anxiety when Francis and Elizabeth invite the newlyweds to spend Christmas at Trenwith.

Demelza gives birth, and resolves to help Verity reconcile with Captain Blamey; Ross welcomes old friend Dr. Dwight Enys to Cornwall; Francis tries to recoup his losses.

With Jim gravely ill in Bodmin jail, Ross and Dwight launch a desperate mission to save him. Demelza is excited to attend a grand ball held by George who is determined to ruin Ross and his smelting company.