Fourteen-year-old Rustam lives with his mother in a village; his father was killed by the Russian mafia. After his father's death, Rustam tries to provide for himself and his mother without resorting to illegal money-making schemes. But his dream is to join a music band. The title of the film refers to an Azerbaijani fairy tale about saving a princess from a house with 40 doors; no one has succeeded in opening the last door, and thus its secret remains hidden. The villagers have named their village the 40th door as well.