Belial (2007)

Ten-year-old Ian Green is a loner from a broken home on the not-so-sunny side of the tracks. A curious wanderer, he comes across an abandoned school at the edge of town. Dark and foreboding, Ian is drawn to the mystique of this new playground. To his surprise, he is not the only one to find this place a new haven. Ian has just stumbled onto the new killing grounds of recently escaped prison convict, Wesson Garr. Once aware of Ian's intrusion, Wesson decides this school isn't big enough for the two of them. A realistic and daring approach to a claustrophobic story of survival.