After the Evil is a cinematic documentary exploring the work of Gitta Sereny, an Austrian-British journalist and researcher who tirelessly probed the dark side of human nature. She spent her adult life trying to explain evil. She did it through an intense process of research, resulting in biographies of Franz Stangl, commander of the Treblinka death camp, of Hitler’s architect and close companion Albert Speer, and of Mary Bell, a child murderer. Sereny, in the film, raises this question: are we all able, one day, to switch to the other side?