In 2009, young Isla Blake disappeared from her sister's birthday party in Northumberland and she was never found.
Fifteen years later, when an updated E-fit image of what Isla would look like now goes viral, everyone begins to suspect that the unassuming Ruby must be Isla Blake.
Enveloped in a swarm of media attention and publicity, including that of Isla's parents Keira and Finn, Ruby is thrust into the centre of a case she had never thought she would be a part of.
As the case unfolds and Ruby begins to question her own identity, the same questions plague her over and over again. Is she Isla? If so, who took her? And what exactly happened to Isla all those years ago?