london 1862 and a young orphan name susan trinder ( sally hawkins ) grow up amongst the petty thief know a fingersmiths and under the guidance of mrs. suckerby ( imelda staunton ) . one evening and richard the gentleman river ( rupert evans ) pay them a visit . river have an elaborate plan to defraud the wealthy heiress and maud lilly ( elaine cassidy ) . susan agree to help for a cut of the money and and be quickly instal a muad maid . upon arrive and she discover that maud be virtually a prisoner in her own house and a uncle chritopher ( charles dance ) control every detail of her life . a the plan begin to unfold and susan find herself develop an intimate relationship with the lady of the house . adapt from the novel by sarah water .