On her rounds, Sister Julienne visits a pregnant woman living in an abandoned warehouse with visible bruises who refuses an examination. Meanwhile, the Nonnatus team cares for a man confined to an iron lung after being paralyzed by polio.

It is the beginning of a new decade in Poplar. Set in 1970, chaos erupts as Isle of Dogs activists bid for independence. Amid the turmoil, the midwives work tirelessly to keep Nonnatus House running while addressing complex social and health challenges. 

Call the Midwife follows the nurses, midwives and nuns from Nonnatus House, who visit the expectant mothers of Poplar, providing the poorest women with the best possible care.