When only the dead have the answers, who can tell you the truth? DI Owen Sheen and DC Aoife McCusker are back working on the reformed Serious Historic Offences Team in Belfast, although the hands-on approach of the chief constable and the political agendas at play are a struggle to manage. And that's before a cryptic message from a retired, and now missing, cop begins to prey on Sheen's mind. The note Tom 'Tucker' Rodgers sent says that they killed his friend, and now they're coming for him. Sheen and Aoife's search for Tucker and the truth places them on the path of the most highly placed IRA double agent of the Troubles, as well as another man with an old score to settle.