The architect entrusts his daughter, Lida, and his son, Taher, to an engineer before his death. The engineer goes to Ahvaz and takes Lida with him to raise her alongside his son Shahram - and the neighbors raise Taher among them. Years later, Shahram rapes Lida, and the the engineer, suspecting that Lida is a promiscuous woman, kicks her out of his house.