While on assignment in Pakistan, Caroline Turner is killed in a drone strike. Her grief-stricken husband, Michael, leaves their cottage in Wales and returns to London to try to build a new life. He quickly develops a close friendship with his neighbours, Josh and Samantha Nelson and their two young daughters. Michael's friendship with the Nelsons marks the beginning of a long healing process, which is interrupted when Michael receives a letter from the soldier responsible for Caroline's death.