The nuns and nurses are tested as they have never been before, both personally and professionally. All around them they see the old East End vanishing, as slum clearances make way for bold new tower blocks to accommodate expanding communities. Their work brings them into contact with a wide range of challenges, from leprosy and stroke, to Huntington's chorea, cataracts and unmarried mothers. Trixie's romance with Christopher continues to develop, while Tom and Barbara enjoy life as a married couple. Nurse Crane finds her authority questioned from an unexpected quarter and Sister Monica Joan is forced to accept her failing faculties. Meanwhile, life for the Turners is turned upside down when Shelagh decides to employ an au pair.