Call the Midwife is making a welcome comeback with three new episodes set during World War Two18:12, 02 Aug 2026Call the Midwife is set to welcome back a familiar face in the forthcoming mini-series, Sisters in Arms.‌The BBC One period drama, launched in 2012, follows the everyday lives of the nuns and midwives at Nonnatus House, who tend to Poplar's medical needs.‌Adapted from the memoirs of renowned nurse and midwife Jennifer Worth, the show was initially set in 1957, when the National Health Service was still a relatively new concept.‌Earlier this year, the fifteenth series aired on BBC One and was set during 1971, depicting developments in medical science and practice as reforms to the NHS threatened Nonnatus House with closure.However, the drama is now rewinding the clock back to the Second World War for a three-part special, Sisters in Arms, which includes a stellar cast, from Sister Julienne star Jenny Agutter as the narrator to returning actress Ami Metcalf.Who was Ami Metcalf in Call the Midwife?‌The original Christmas special of Call the Midwife, which aired on December 25, 2012, followed on from the first season and told the story of Lynette Duncan, a teenager who found herself pregnant and scared.The 15-year-old hid her pregnancy and heartbreakingly gave birth in an abandoned house, putting her and her baby's lives in grave danger.Lynette then left her son at the doors of Nonnatus House to be cared for by the nuns and nurses, while she hobbled home in pain and bleeding.‌The next morning, Trixie (Helen George) and Cynthia (Bryony Hannah) find the baby boy blue and hardly breathing, but they manage to save his life.They call the baby Raymond after the convent, and the news of his abandonment soon reaches the newspapers, leaving the Poplar community in shock.Eventually, Lynette is identified as Raymond's mother, and he is accepted into her family, with her mum and dad allowing their daughter to bring him home before he was adopted.‌Ami Metcalf played Lynette in the first festive special and will return as Betty Buckle, the first wife of Fred Buckle (played by Ciaran Bowling), in the prequel.What is the Call the Midwife prequel about?It's September 1939, and Sister Monica Joan (Helen Schlesinger ) is in her prime and works alongside Sister Julienne (Helena Wilson) and Sister Evangelina (Amy Booth-Steel ), who are young and zealous, and Nonnatus House is the beating heart of Poplar.‌There is no gas and air, no penicillin, no cure for TB, and no welfare state, but life gets even harder when World War II is announced.Together with Sister Alice, played by Julie Hesmondhalgh, and local GP Dr Kit (Bally Gill), the nuns dedicate their lives to mothers, babies, and those living in poverty.Three young midwives complete the team, including Sybil (Lizzie Back), Olive (Ellie McKay), and Marianne (Liv Andrusier), who receive a baptism of fire as the blackout and the Blitz take hold.Article continues belowWhile bombs rain from the sky, women give birth underground, families are shattered, children run wild, and whole streets are reduced to rubble.But courage, compassion, and resilience triumph as the community unites in its efforts to survive. The air date for Sisters in Arms has yet to be confirmed.Call the Midwife is available to stream on BBC iPlayer