With autumn on its way, the appetite for change is rife across Poplar. As Dr Turner shares his excitement about the impending release of the contraceptive pill, not all of his counterparts at Nonnatus House are as keen for the social change it may bring. Meanwhile, Patsy realises that change isn't always for the best as she struggles to help a transient Bargee woman, who is determined to give birth among her own community, rather than the modern comforts of the maternity home. As a huge storm threatens Poplar, Nurse Crane is called upon to assist a new mother in a post-natal emergency, the danger bringing a once-distant young couple closer as a result. As the storm subsides, it brings with it the welcome return of Sister Evangelina, herself changed by the time she has spent away from Nonnatus House.