Out of the blue, private investigator and ex-soldier Lee Arnold receives a visit from an old army mate. Abbas al'Barri worked as a translator with him during the Second Iraq War. Now living in Ilford with his family, Abbas is convinced that he's had a message from his estranged son Fayyaad, who was radicalised and was last thought to be fighting for ISIL in Iraq. Does Fayyaad's message indicate a change of heart? Abbas is desperate for Lee's help in establishing some contact with him, a point with which Lee's Muslim assistant Mumtaz might be able to help.

From the bright lights of the Western world, to the murky online recruitment techniques of radical Islamism, Lee and Mumtaz have little to guide them in who to trust as they begin a journey into the belly of the beast.