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.

Mother Mildred and the Nonnatus House team head to the Outer Hebrides in response to a nursing shortage.

The circus comes to Poplar, putting a magical spell on its residents. A delighted Shelagh is reacquainted with an old friend, and Trixie receives an unusual gift.

Christmas promises to be a memorable one at Nonnatus House as Lucille and Cyril prepare for their upcoming winter wedding. The Nonnatus team are faced with their busiest Christmas Day ever as the Maternity Home is filled with expectant mums-to-be, each with their own challenging case. Luckily Mother Mildred is on hand to support the team.