Tired from a war in America, Ross Poldark returns to his land and his family. But the joyful homecoming he has anticipated turns sour, for his father is dead. But his sympathy for the destitute farmers of the district leads him to rescue an urchin girl and take her home -- an act which alters the whole course of his life.

Cornwall 1794. The birth of a son to Elizabeth and George Warleggan serves only to accentuate the rift between the Poldark and Warleggan families. And when Morwenna Chynoweth, now governess to Elizabeth's eldest son, grows to love Drake Carne, Demelza's brother, the enduring rivalry between George and Ross finds a new focus for bitter enmity and conflict.

The tenth book in the legendary Poldark saga Cornwall, 1813: A silver cup lies half-forgotten in a dank cave, amongst a pile of stolen goods. Yet the tiny vessel and its inscription haunts the lives of the still-feuding Poldark and Warleggan families, as Ross, Demelza and the ambitious and powerful Sir George Warleggan watch their children make the decisions that will shape their destinies. In the closing years of the wars against Napoleon, for Jeremy...

The Twisted Sword, the eleventh novel in Winston Graham's classic Poldark saga, now a major TV series from Masterpiece PBS.

Cornwall 1815
Demelza sees a horseman riding down the valley and senses disruption to the domestic contentment she has fought so hard to achieve. For Ross has little option but to accept the summons – and travel to Paris with his family, as an 'observer' of the French armed forces.
Parisian

...

The Poldark family awaits the return of Ross from his mission to Wellington's army in Portugal. But their ordered existence ends with Jeremy Poldark's dramatic rescue of a stranger from the sea. Stephen Carrington's arrival in the Poldark household changes all their lives. For Clowance and Jeremy in particular, the children of Ross and Demelza, Stephen's advent is the key to a new world-- one of both love and danger.

Ross plunges into a highly speculative mining venture which threatens not only his family's financial security but also his turbulent marriage to Demelza. When Ross and Elizabeth's old attraction rekindles itself, Demelza retaliates by becoming dangerously involved with a handsome Scottish cavalry officer. With bankruptcy an increasingly real possibility, the Poldarks seem to be facing disaster on all fronts.

Marnie, a compulsive thief and liar is caught. Her captor impulsively marries the frigid, disturbed girl in hopes of helping her and discovering the reasons for her ongoing anti-social behavior.

It is a new century and with it comes the promise of a hopeful future, but the past casts a long shadow over Cornwall. Following the death of Elizabeth, Ross Poldark resolves to put Westminster behind him and spend more time with the people he loves. However, when an old friend emerges with a plea for help, Ross is compelled to challenge the establishment again.

"A compulsive liar and thief, Marnie ... winds up impulsively marrying the very man ... she attempts to rob. When a terrible accident pushes her over the edge, her husband struggles to help her face her demons and her past"--Container.