Adapted by writer Julian Fellowes, Doctor Thorne by Anthony Trollope, is the story of Doctor Thomas Thorne, who lives in the village of Greshamsbury in Barsetshire, with his beautiful niece, Mary, a girl blessed with every gift except money. Mary Thorne has grown up alongside the Gresham sisters--Augusta, Beatrice and their handsome brother Frank--whose home is the great house and estate at Greshamsbury Park.

When the terrifying Lady Arabella Gresham discovers that her darling son, Frank, has fallen in love with Doctor Thorne's penniless niece, she is horrified. Her husband has frittered away the family fortune and is only being kept afloat by very favourable loans that Doctor Thorne has secured from a railway millionaire, Sir Roger Scatcherd. However, Sir Roger is drinking himself into an early grave and the financial future is uncertain, so Lady Arabella believes it is her son's duty to make a rich marriage to save the family estate and launches a campaign to secure her son an heiress for a bride.