In 1783, Ross Poldark returns from the American wars to his native Cornwall to find his home in shambles and his betrothed Elizabeth engaged to another.

Ross determines to put Nampara back on track and get his mine Wheal Leisure running again. Ross decides to take young Demelza Carne into his house as a servant.

Demelza has taken over running Nampara; Elizabeth and Francis now married have had a child; Ross has to defend Jim Carter in court but to no avail as he is sent to prison.

After another infidelity from Francis, Elizabeth decides to leave Francis for Ross after his father's death — but Demelza's pregnancy complicates everything.

Ross and Demelza, now married, celebrate the birth of their daughter, Julia. A travelling troupe of performers stages a play at Nampara, and Mark Daniel falls for a young actress named Keren.

When Jim Carter becomes seriously ill in prison, Ross worries that he'll die before completing his sentence.

Young Geoffrey Charles is stricken with a serious illness; when Francis also falls ill, Demelza assists Elizabeth in caring for him.

Mark Daniel learns of Keren's affair with Dwight Enys; Ross helps Mark avoid capture by the authorities.

After Ross is released on bail on charges of looting a wrecked ship, the Warleggans stubborn witnesses in order to have him legally executed.

Francis' botched suicide attempt leaves him in deep melancholia as the Warleggans' parade of suborned witnesses darkens Ross' prospects for acquittal.

Ross rehires Jud, reestablishes his friendship with Francis, and becomes involved with smugglers in the hope of raising money to exploit a new vein.

Warleggan's minions beat Jud to death in revenge for his changing his testimony. Francis and Ross plan to open Wheal Grace using Warleggan money.

After the birth of Ross and Demelza's son, Francis accidentally drowns in Wheal Grace after supposedly discovering a new vein of precious copper.

Ross tries to locate Mark Daniel in hopes that he will remember the location of the copper vein he found while hiding in Wheal Grace.

Ross's hopes for a new vein of copper are shattered, and his distress amplifies when he finds out Elizabith is to wed Warleggan, resulting in the break of their vows.

Warleggan evicts hundreds of tenant families in his efforts to exert power, and Ross discovers a valuable vein of tin in his depleted copper mine, Wheal Grace.