When the German army found themselves desperate for a typhus vaccine, they turned to Rudolf Weigl. The success of Weigl's techniques gave him cover during the Nazi's reign, so he hired otherwise doomed men, protecting them from atrocity. Among the scientists saved was a gifted Jewish immunologist named Ludwik Fleck. Condemned to Buchenwald and pressured to recreate the vaccine, Fleck had to make a choice between his scientific ideals or the truth of his conscience.