Martyrs (2008)

Review: IMDB Pastina
Synopsis: MovieWeb
Trailer: TrailerAddict
France. A night at the beginning of the 1970s. Lucie, a little girl missing for over a year, is discovered wandering by the side of a country road. Near catatonic, she can say nothing about what has happened to her. The cops quickly find the place in which she's been incarcerated - a disused slaughterhouse.

Every indication is that she never once left the empty, freezing room in which she was imprisoned. Filthy, starving, dehydrated, the child's body nonetheless bears no traces of sexual abuse - this was no pedophile abduction, but something far stranger. What happened in that icy room? And how did Lucie escape?

This is a story about a young woman's quest for revenge against the people who kidnapped and tormented her as a child leads her and a friend, who is also a victim of child abuse, on a terrifying journey into a living hell of depravity.