As Christmas approaches, a bout of influenza sweeps through both Nonnatus House and the Turner family. When Mother Mildred declares that God is calling her to set up a branch house in the Outer Hebrides, it seems an ideal opportunity for the nuns and midwives to convalesce in the bracing Scottish air. As they recover, they will also be able to help the island, where there is a nursing and doctor shortage.
Sister Monica Joan associates the Outer Hebrides with St Eustace's White Stag, a symbol of Christ, and is thrilled at the idea of travelling there. However, she soon discovers to her annoyance that she is being left behind with Sister Hilda and Sister Frances.
Within a week, Dr Turner, Shelagh, Mother Mildred, Trixie, Sister Julienne, Valerie and Lucille set off on their journey to the Outer Hebrides, where they are to stay in a freezing cold converted church. As the team set about establishing an antenatal clinic and treating the local population, they must battle not only the weather and bleak terrain but also the suspicions of some of the islanders.
Meanwhile, in Poplar, Reggie has come home for Christmas and finds one of Violet's presents for him: the Book of Guinness World Records. Inspired by the triumphs of others, Reggie decides that he too will try to break a world record.
