Amber
Ben and Sarah Bailey are recently separated yet doing their best to get on with their lives while remaining good parents to their children, Amber and Eamon. Then, in one day, their lives are turned upside down when Amber fails to return home.
Sarah
When fourteen-year-old Amber disappears, her mother, Sarah tries desperately to track her down. Months pass with no solid evidence and Sarah reluctantly allows her journalist friend to write an article on the disappearance, which she will later regret.
Maeve
Maeve Flynn Dunne is a weary socialite who has recently profited from her friendship with Sarah Bailey. When she is contacted by a prisoner who claims to have new information about Amber, she sees an opportunity to redeem herself in the eyes of Sarah.
Charlie
Charlie Huang is an irregular migrant in debt to the gang who brought him to England from China. When he comes into possession of Amber's stolen phone, Charlie tries to mail it to Ben. But Ben is suspicious of the stranger.
Ben
With a new job and boyfriend Sarah seems to be moving on with her life, but Ben is still convinced that Amber is alive and, in a moment of reconciliation with his ex-wife, celebrates Amber's birthday in her absence.