With Nonnatus House scheduled for demolition, Jenny (Jessica Raine), Chummy (Miranda Hart) and Sister Julienne (Jenny Agutter) search for a new location nearby, while Jenny's relationship with Alec continues to blossom. But an outbreak of polio affects the nurses and nuns more than they could have imagined. Hop on a bicycle and share sadness and joy, tears and humor, struggle and survival in this award-winning drama, based on the best-selling memoirs of former nurse Jennifer Worth.