The episode opens in 2005 with Jennifer Worth at home preparing for Christmas with husband Philip. She reminisces about the friends and colleagues of her youth at Nonnatus House, and as she talks we cut back to 1959.

As Poplar celebrates a white Christmas, an unexpected SOS call from the Mother House interrupts festivities. Hope Clinic, a tiny mission hospital in South Africa that has links to the Order, is threatened with closure. Sister Julienne swiftly procures the help of Sister Winifred, Trixie, Barbara, Nurse Crane, Dr. Turner, Shelagh, Fred and Tom Hereward and they are soon transported to South Africa to try and save the clinic.

As Poplar prepares for Christmas, the nuns leave for the Mother House to vote in a new mother superior and to help care for a group of Chinese orphans. Meanwhile, Trixie returns to Poplar refreshed and is shocked to discover that many mothers no longer want to give birth at home.