Stalked by a masked figure through a city that is changing around her, Emmie Keyes must do unspeakable things in order to survive in the follow-up to Tethered Twins. Carrying on immediately after the shock ending of Tethered Twins, she receives a message from someone she thought was lost forever which sees her return to the broken city of London in a search for answers. With the help of the Deck, Grace, R&R and new allies, Emmie discovers secrets that have been buried beneath the city of London for centuries. But those secrets come at a cost and she must fight forces on the surface, deep underground and within her own body if she wants to survive. As the stakes raise ever higher it becomes quickly apparent that sacrifices must be made for the greater good but can she bring herself to make them before all is lost?