Cornwall, 1783. Ross Poldark returns from the battlefield to find his father dead.

Ross plans to reopen his family mine with Francis. Demelza struggles to fit in at Nampara.

Rumours spread of a scandalous relationship between Ross and Demelza.

News of Ross and Demelza's marriage spreads, damaging Wheal Leisure's prospects.

With Jim gravely ill in jail, Ross and Dwight launch a desperate mission to save him.

Francis wrongly blames Ross for helping Verity elope with Andrew Blamey.

George expands the Warleggan empire, launching a new ship and bankrupting Carnmore.

Ross prepares for his trial as Demelza and Elizabeth try to help his cause. George does everything in his power to harm Ross, Francis wrestles with his conscience, and Dwight clashes with an entitled heiress, Caroline Penvenen.

An informant in the smuggling ring poses a serious threat to all, and George buys Ross's debt to finally crush him. Meanwhile, Caroline returns to Cornwall to make an announcement, but it is Elizabeth who reveals a great secret.

Ross tries to help Francis's family financially, but George calls in Ross's debt. Demelza toils loyally to protect all at Nampara, and Dwight and Caroline continue to meet in secret.

Ross and Dwight stand trial for their part in the smuggling. A new tin lode gives Ross renewed hope in Wheal Grace, but it is George who is there for Elizabeth when her mother falls ill and deals Ross a bitter blow.

Ross and Demelza look to forget the past and rebuild their marriage, but new arrivals threaten their fragile reconciliation.

Sam and Drake provoke Trentishoe and Ross's stubbornness gives George the upper hand. Meanwhile, a great naval battle leaves Dwight's fate in question.

Ross is ordered to leave Roscoff under threat of execution. He travels with Tholly to meet his contact in France, but finds information about Dwight's fate comes at a high price. Sam leads a congregation of methodists in protest outside the church - only to face broken promises from George, who revokes their lease on the meeting house, which leads them to turn to Elizabeth for help. Geoffrey Charles has some words of advice for Drake, who has shared a moment of intimacy on the beach with Morwenna.

George proves merciless as the new magistrate, and Clowance is christened. Ross discovers the means to both help Dwight and combat Cornwall's famine.

Ross is adamant George will lose in the election and determines to get a headstone made for Agatha's grave, something Trenwith has neglected. George, meanwhile, questions Dwight over Valentine's legitimacy and - paranoid and jealous - shuts himself to Elizabeth, as Rowella begins to seduce Osborne Whitworth and Demelza receives tokens of Hugh's affection. Sam continues to pine after Emma, as Dwight instructs Osborne to forego intercourse with Morwenna and Cary informs Lord Falmouth that the Warleggans will be opposing Falmouth in the election. Ross returns from his mine to discover Hugh Armitage at Nampara with Demelza - and this time Hugh's attention does not go unnoticed..

The Poldarks determine to get their relationship on track and the Enyses announce they're expecting a baby. Hugh's worsening health threatens his chance to stand in the election, and the prospect of him remaining in Cornwall adds pressure to the Poldarks' fragile marriage. At the Sawle Feast, Tom Harry challenges Sam to a wrestling match. When Emma offers herself as the prize, Sam accepts.

Ross faces the challenge of Parliament and the Warleggans refuse to accept defeat. In Cornwall, Demelza contends with a failing mine and fixing Drake's broken heart. Dwight and Caroline welcome a baby daughter. Ossie meanwhile tends to a dying parishioner and George hosts an extravagant party at Trenwith.

Ross is reunited with his family at home, but tragedy strikes in Cornwall. Dwight tells Caroline some devastating news about Sarah. Ossie is seen visiting Rowella by her husband Arthur, who grows suspicious. Emma returns to give Sam her answer, whilst Drake is persuaded into courting Rosina.

After it is revealed that Nathaniel Pearce embezzled Pascoe’s client’s funds, the Warleggans take action. In London, Ross finds Geoffrey Charles led astray by Adderley. Sam convinces Drake to return from exile following his abandonment of Rosina and Morwenna’s subsequent rejection and Morwenna reveals some news. Dwight meanwhile helps in the development of Truro’s infirmary.

Ross Poldark returns home after American Revolutionary War and rebuilds his life with a new business venture, making new enemies and finding a new love where he least expects it.

The Poldarks look forward to life together in peace, but a plea from his old army colonel, Ned Despard, compels Ross to the capital. Arriving in London, he finds a city gripped with paranoia, and is determined to save Ned from the conspiracy that imprisoned him.

As George expands his power through a shady alliance, the Poldarks become caught in a deadly web.

Ross's tenacity in helping Ned bears fruit, but not without cost. Hanson’s presence in Cornwall raises suspicion and as Demelza wrestles with how best to equip the community to look after itself, Morwenna lends herself to the cause and finds new hope.

Ralph seeks to ruin Ned as rebellion stirs and the Poldarks are trapped in the middle.

George’s cabal moves to ruin the Poldarks, and Morwenna wrestles with a heavy decision.

Ross fights for Ned’s life as Demelza uncovers betrayal and the young lovers take flight for a future together.

Ross discovers a French plot, and George finds himself at the mercy of Joseph and Ralph.

With the fate of his nation in the balance, Ross must gamble everything to protect his country and those he loves.