The hugely successful stories starring Jenny Agutter (The Avengers), Pam Ferris (Harry Potter and the Prisoner of Azkaban), Helen George (The Three Musketeers), and Linda Bassett (Spies of Warsaw), returns with more touching and compelling stories from the nurses and nuns of Nonnatus House. In this series, Sister Monica Joan (Judy Parfitt) goes missing at Christmas time leaving the nuns and nurses distraught. Trixie, having battled through her issues with alcohol, finds a new purpose in her keep fit classes. And could friendship blossom into something more for vicar Tom Hereward (Jack Ashton) and Barbara (Charlotte Ritchie)? Meanwhile, a string of babies born with severe and devastating deformities casts a dark shadow over the entire team at Nonnatus House as they struggle to understand why.