After a friend's son is found dead, Soviet secret-police officer Leo Demidov (Tom Hardy) suspects his superiors are covering up the truth. When Leo dares to raise questions, he is demoted and exiled to a provincial outpost with his wife. There, Leo soon discovers other mysterious deaths with similar circumstances and convinces his new boss that a deranged serial killer is on the loose - and must be stopped before he strikes again in this electrifying thriller.