As social improvements move forward in South Riding, Robert (David Morrissey) faces ruin after a principled stand against political corruption, and Sarah (Anna Maxwell Martin) confronts a crisis — both personal and professional.

As social improvements move forward in South Riding, Robert (David Morrissey) faces ruin after a principled stand against political corruption, and Sarah (Anna Maxwell Martin) confronts a crisis — both personal and professional. Penelope Wilton also stars.

MASTERPIECE CLASSIC "South Riding" series premieres Sundays, May 1-15, 2011, 9:00-10:00 p.m. ET.