A citadel is usually defined as a fortress—typically on high ground—that protects or dominates a city. But what if, like in this debut film by Irish writer-director Ciaran Foy, the citadel is filled with filthy, murderous, syringe-wielding children? Creepy, mouth-breathing, feral preteens, wearing dirty hooded sweatshirts, who want to kidnap your baby and put it in a cage? What if the only thing this child-monster-filled citadel, sitting quiet and stoic in an impossibly dreary London slum, dominates is one terrified man? What if he’s terrified because these child-monsters killed his pregnant wife? What if this one terrified man develops a real-life anxiety and becomes an agoraphobic who cannot leave his house for fear that the children will take his newborn daughter? What if he, in addition to dealing with this agoraphobia, has to figure out how to take care of a brand-new baby by himself? What if a nice nurse from the hospital tries to cure him and drag him out of the safety of his apartment? What if, at this point, the child-monsters do indeed come for his baby, confirming his worst, most intense fear? What if a renegade priest decides to help the terrified man by dragging him inside of the citadel—into the heart and home of fear and Terrorville? What happens then? You have to see the movie. Diehard horror fans will approve.