Public service announcement: If you are planning to binge a few episodes in a row of “Call the Midwife ... married fellow shopkeeper Violet (Annabelle Apsion), with whom he’s still besotted.

The nuns and midwives of Nonnatus House are off on a magical Christmas adventure to the Outer Hebrides. But when they encounter stubborn locals, a gaggle of wayward sheep and a dire shortage of ...