The winds of change are blowing through Poplar, as a new government paper calls for the eradication of small hospitals in favour of large general hospitals. Dr Turner and Shelagh are informed that an inspection of the maternity home will decide its fate. Sister Ursula has her own anxieties about the efficiency of Nonnatus House, so she introduces a new 20-minute rule for all antenatal and postnatal house visits. Barbara struggles the most with this, as she is drawn into helping a first-time mother from the Chinese community. It soon becomes apparent that the shortened visit might have allowed a serious oversight. With the future of the maternity home hanging by a thread, serious questions are raised over Sister Ursula's suitability for her role. Meanwhile, Sister Monica Joan has started disappearing for long periods of time and there are growing concerns for Sister Mary Cynthia's whereabouts.