When Rose Brown's husband is killed at Dunkirk in 1940 she feels as though she's lost a part of herself Rose can't imagine the future without Ray but she's certain he would have wanted her to start again She decides to volunteer as a postwoman in West London & when she courageously rescues a young boy from a bombed-out house & takes him home she finds a new sense of purpose Traumatised from losing his mother in the ruins seven-year-old Alfie is also rebellious & withdrawn However he touches the hearts of Rose's family & with kindness patience & love they eventually win his trust But then a handsome stranger Johnny Beech turns up on the doorstep looking for his son & everything changes