An agoraphobic father faces his greatest fear in order to protect his infant daughter from the same gang that brutally murdered his wife in this urban psychological thriller from first-time feature writer/director Ciaran Foy. When a gang of hooded thugs lay siege to Tommy Cowley's apartment, his pregnant wife suffers an agonizing death. In the aftermath of that trauma, Tommy (Aneurin Barnard) struggles to raise his infant daughter alone while suffering a crippling fear of the outside world. But as Tommy's therapist attempts to help him move past his debilitating agoraphobia, the hooded hooligans return, seemingly intent on taking his daughter as well. Desperate, Tommy reaches out to a local priest, who reveals that the ubiquitous assailants may not be human. Now, the fate of his newborn daughter hanging in the balance, Tommy, the Priest, and a mysterious blind child prepare prepares to brave the inner depths of a derelict apartment block known as the Citadel and confront the murderous devils who torment him every waking hour.