DI Owen Sheen vowed never to return to Ireland, but he needs answers to the questions he has surrounding his brother's death. On loan from the Met to the PSNI, he is meant to be setting up a new Historical Offences Team, but instead he finds himself partnered with DC Aoife McCusker to work on her first murder investigation. As the investigation begins to unravel into chaos, its roots deep in the dark past of the Troubles, will Sheen be able to put his personal agenda aside? And will McCusker keep her career long enough to crack the case and prove herself as a detective?