The awful genius of this quietly horrifying film lies in its implication. Michael (Michael Fuith) is a slight, balding, thirty-ish man who lives in an anonymous German suburb and works at an insurance office where he's about to get a promotion.
He has a sister and mother who keep in touch, though he never visits. What nobody knows is that he keeps a 10-year-old boy (David Rauchenberger) prisoner in his basement. When he brings the boy upstairs they enact a grotesque version of domesticity – having dinner, doing the dishes, watching TV. At Christmas they decorate a tree and sing "Silent Night" together. But he also rapes him.
The director Markus Schleinzer presents this chronicle of torture in a dispassionate, near-documentary style, observing Michael's routine and, heartbreakingly, the boy's lonely captivity: told that his parents don't want him, he nevertheless writes them letters which go undelivered. Minute by minute we wonder if the boy will try to escape, but his jailer seems too meticulous to be caught out.
As in Michael Haneke's films, the horror exists just out of sight, gnawing away at our nerves, waiting to spring. The experience of it will be too gruelling for most, though Schleinzer's direction and Fuith's performance have worked out the material with undeniable skill; we have been witness to a paedophile rapist and "monster", but also, just as disconcertingly, to a well-regarded human being.