In June 2014 so-called Islamic State fighters occupied huge areas of Syria and Iraq, overwhelming the Yazidi settlements grouped around Mount Sinjar. Yazidi men were killed, young women forced into slavery. This film tells the story of Shirin and Lewiza, two Yazidi women captured by IS, who escape to Germany thanks to the intervention of Dr Jan Kizilhan, an expert on trauma. In all, he brings a thousand women and girls - all victims of IS sexual violence - from the refugee camps in Iraq to his clinic in the Black Forest for treatment. Yazidis believe that sexual contact with a non-Yazidi, even through rape, results in a loss of Yazidi identity. As a way of destroying the community, the rape of women and girls is almost as effective as the execution of the men. Kizilhan believes it will aid the women's recovery if they know that the enormity of what happened to them is recognised. With international lawyer Philippe Sands he explores the possibility of a genocide trial. We observe investigators gathering evidence of IS crimes, meet a German prosecutor intent on bringing perpetrators to justice, and consider the relevance of ongoing trials in Iraq.