The convent comes under threat of demolition. Fred's pregnant daughter and her young son come and stay with him. Jenny is wooed by a new love interest. Chummy and PC Noakes prepare for the arrival of their baby.

After the closure of Nonnatus House, the nuns and midwives finally move into their new premises. Sister Winifred arrives from the Mother House. Jenny is worried about new mother Merle’s mental state and the welfare of her baby who isn't feeding properly. Dr Turner is worried that it could be something more serious.

Trixie's feathers are ruffled when Jenny is promoted, but the new Acting Sister has more to worry about after a mother-to-be reveals the baby she is carrying doesn't belong to her husband - and to complicate matters, the real father is black. Cynthia is inspired by a lecture on natural childbirth, convinced it will help an overly anxious patient, while Alec and his friends try to persuade Jenny to join them on a CND march.

Jenny has an eventful few days, starting with a patient who as well as having herself to worry about, is also struggling to cope with her mother, an agoraphobic who hasn't been outside for at least 12 years. On top of that, Alec asks the midwife to accompany him to Brighton for the weekend, leaving her wondering if his intentions are strictly honourable. However, things soon take a tragic turn. Meanwhile, Shelagh joins the local choir to take her mind off her problems.