Dark Waters (2010)

A young man, Niall, previously missing for over a month, returns to his small Welsh town. What he finds is a world that's changed beyond his reckonings. His girlfriend is dead and in the grave, his old friends treat him with suspicion and contempt. Only his friend Rob seems willing to help him unravel the mystery of his missing 28 days. Through flashbacks we witness snapshots of happier times, and of his girlfriend, Josey's inexorable slide into drug addiction. Cormac is the local drug lord, intent on making Josey his own. A fatal error of judgment is to blame for her death. Niall, on a tense night out with his friends, comes face to face with Cormac and his gang in a bar. What follows is night of terror that reveals the tragic truth about Niall's missing weeks.