In the Soviet Union in the late 1930s, Alexander Kornev is a young and idealistic prosecutor, eager to carry out the wishes of the Stalinist government. Surprisingly, he receives a letter from a detainee—written in blood on cardboard—who was once a highly regarded prosecutor himself. Kornev believes the man but will soon discover that the needs of an individual are contrary to the oft-unstated goals of the state, and Kornev finds himself trapped in a Kafkaesque nightmare from which he will never recover. Sergei Loznitsa’s political thriller is a paranoid triumph, a parable for our times anchored by brilliant performances.