Whilst anxious to build their own Methodist chapel, the Carne brothers work well at the mine, though they defy Ross by entering Warleggan's estate, where Drake meets and is captivated by Morwenna. Along with Caroline, Verity attends Valentine's christening where she unsuccessfully attempts reconciliation between the Warleggans and Ross. Both women are alarmed to hear their husband's ships are missing at sea, but Verity's spouse Andrew is found alive and well. Despite unexpected support from the Reverend Halse, Ross refuses to put himself forward as magistrate replacing the late Ray Penvenen, giving Warleggan the victory. Later Ross hears that Dwight has been cast ashore in revolutionary France and, with his friend Tholly Tregirls, sets out to rescue him.

Tholly takes Ross to a French port where republican soldiers are executing their prisoner. They meet Jacques Clisson, who gives them information about Dwight's incarceration but, threatened with prison himself, Ross returns home without his friend. Banned by Warleggan from using his church, the Carne boys find a venue for their Methodist meeting house, but are again thwarted by Warleggan through a legal loop-hole and are ultimately saved by Demelza, who allows them to use a barn on Ross's land. The Warleggans move to Truro, where even Elizabeth is shocked by the immoral social climbing of her newly appointed magistrate husband, and starts to feel isolated, but their absence leaves Morwenna, encouraged by Aunt Agatha and Geoffrey Charles, to continue meeting Drake.

Guests come to Ross and Demelza's daughter Cowance's christening. Morwenna and Geoffrey Charles are called away for Christmas. George plots to marry Morwenna off for political gain, but her heart belongs to Drake. Ross, Demelza, and Caroline find a way to feed the poor. Dwight continues to suffer in French prison.

Ross and friends embark on another expedition in attempt to free Dr. Enys from French prison. George tries to elevate himself by disparaging Ross. Morwenna finally decides her feelings for Drake aren't worth the potential repercussions.

Whitworth's sexual demands on Morwenna are making her life a misery. When she falls pregnant he brings in her sister Rowella to help her, a girl who immediately spots his weakness. To give the broken Drake a positive in his life, Ross sets him up with his own smithy. At the Enys's public union both Elizabeth and Demelza notice Morwenna's unhappiness. Warleggan is perturbed when Hugh's uncle, Lord Falmouth, singles Ross out as a hero, and Sir Francis Bassett, declaring him a man of the people, proposes him as a member of parliament. Ross declines, allowing Warleggan to assume the candidacy, much to the annoyance of Demelza, who becomes closer to the besotted Hugh Armitage. Aunt Agatha dies, but her final act is to suggest to Warleggan that Ross is the true father of his son Valentine.

When French ships are seen off the coast, Sir Francis appoints Ross to lead the volunteers ready to repel any invasion, to the annoyance of Warleggan. George is further angered when Sir Francis criticizes his use of his parliamentary privilege for his own benefit. He vents his rage on Drake, having him brutally assaulted and his forge destroyed. Demelza, disappointed by Ross's apparent failure to avenge her brother, spends more time with Hugh, while Ross quells a rebellion against Warleggan by agreeing to stand for parliament himself. Rowella finds herself pregnant by Whitworth, and blackmails him into paying a young local, Arthur Selway, to marry her, giving Morwenna the strength to rebel against him. Elizabeth also revolts against her cruel husband, who begins to lose his cocky self-assurance, whilst Demelza and Ross go to bed with doubts on either side.

With Hugh's rapidly failing health eliminating him from standing in the election, his uncle, Lord Falmouth, thanks to Caroline and Demelza, joins with Sir Francis in agreeing that Ross should oppose Warleggan as the prospective member of parliament for the district. The result is a triumph for justice but Demelza must make an admission to Ross and, for her brothers, the path of true love continues to run anything but smoothly.

Ross is now member of parliament for Truro and making compassionate speeches opposing slavery and the use of child workers. Inevitably Warleggan, smarting from his defeat, links up with the disreputable Monk Adderley for revenge on Ross and a seat of his own whilst Whitworth seeks another way to discredit him. Returning to Cornwall, where Caroline has given birth to a daughter Sarah, Ross is called upon to save an ailing mine and also pays a visit to Elizabeth.