Amen. 2002

Directed by Costa-Gavras | Starring: Michel Duchaussoy, Mathieu Kassovitz, Sebastian Koch, Ulrich Tukur

Kurt Gerstein—a member of the Institute for Hygiene of the Waffen-SS—is horrified by what he sees in the death camps. he is then shocked to learn that the process he used to purify water for his troops by using Zyklon-B, is now used to kill people in gas chambers.