Call the Midwife: Sisters in Arms wrapsFilming has completed on a three-part special expected to screen at Christmas. The BBC has revealed new pictures of the cast for Call the Midwife: Sisters in Arms, to mark filming wrapping on the three-part special to screen at Christmas (UK). Julie Hesmondhalgh, Helena Wilson, Ellie McKay, Liv Andrusier and Lizzie Back are all seen for the first time on set. In September 1939, Sister Monica Joan is in her prime, Sister Julienne and Sister Evangelina are young and zealous, and Nonnatus House is the beating heart of Poplar. But I was surprised how many new emotions Call the Midwife: Sisters in Arms sparked.