Whip-smart GP Mona Harcourt (Archie Panjabi) lives a charmed life at the heart of a loving family in London alongside political lobbyist husband Guy (Jack Davenport). But on the same day that a terror attack strikes West London, she receives the devastating news that her brother has been kidnapped in Pakistan. As the shock resonates through the family and buried secrets come to light, Mona is drawn into a tangle of betrayal, conspiracy and murder. One way or another, she must find a way to protect herself, her career and her family as, one by one, they are all put at risk. But just how far is she prepared to go to keep her loved ones safe?