The Nonnatus community is rocked when the Kelly family's new born son dies tragically in unexplained circumstances. Cynthia, who had attended the birth, comes under intense scrutiny from the police and the pregnant women of Poplar. Despite reassurances from her friends and colleagues, Cynthia questions her own abilities and the immense strain takes its toll on her work and health. Now fully ensconced in married life with PC Noakes, Chummy's decision to pursue her dream brings about a different sort of pressure as exciting changes lie ahead for the couple. Meanwhile, a chance encounter returns Jimmy to Jenny's life with surprising results.