Between September 16 and 18, 1982, for two nights and three days, the killers of Sabra and Shatila went about their heinous crimes. In the end, they had murdered between 1,000 and 3,000 Palestinian civilians, predominantly women, children and old people. The precise number of victims - both those killed and those missing - is not known to this very day. The perpetrators primarily originated from the ranks of the Forces Libanaises, a Christian militia affiliated to Israel. The logistics for this massacre were provided by the Israeli Army, under the auspices of the former Minister of Defence and current Minister President, Ariel Sharon. In 1982, the massacre in the Lebanese Palestinian camps deeply shook the public throughout the world, but today it has been (almost) entirely forgotten. This is despite the fact that it is a role model for all the massacres that followed: for example that in Rwanda or those committed during the Yugoslavian wars. Again and again, the unanswered questions surface: what drives people to such excesses of brutality, and how are the perpetrators able to live on? Massaker is - both in contents and aesthetically - a psycho-political study of six perpetrators, who participated in the massacre of Sabra and Shatila both on orders and on their own personal initiative. The film intertwines the mental dispositions of the killers with their political environment and broaches the phenomenon of collective violence through their accounts.