Filming has begun on Call the Midwife: Sisters in Arms!   A brand new prequel series takes us back to Nonnatus House… but with World War II on its way, the community must pull together if it’s going to survive.     Coming soon to #iPlayer   #CallTheMidwife #SistersInArms     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. Together with Sister Alice, and local GP Dr Kit, the nuns dedicate their lives to mothers, babies and the poor. But there is no gas and air, no penicillin, no cure for TB, and no welfare state. Then war is declared - and life gets even harder.