Overview: As season four begins, nurse Sarah Nordmann and the wealthy Bligh family face new challenges amid sweeping social change in 1950s Australia. Villainous Regina has finally ensnared Bligh patriarch and political aspirant George in marriage, but she continues to plot against Sarah, exploiting the rising fear of Communism to target her rival. As Sarah teams up with formidable dowager Elizabeth to expose Regina, James and his estranged wife, Olivia forge a fragile peace, and Anna strives to advance her literary career.