[1] The story of the film is based on the murder of Yazdgerd III, the last emperor of Sasanian Persia, who while being hard pressed by the Arabs on his western flank, fled to Marv where he was slain by a miller in a mill, in which he had been taking refuge.
The film begins with the Zoroastrian high priest (magus) of the Persian Empire, accompanied by the imperial army commander entering the mill to try the miller accused of murdering the emperor.
The miller, his wife and his daughter, while trying to exculpate themselves, all express a different version of the same incident.
[2] A central theme in the film is the social disaffection among the general population of Persia at the eve of the Arab Islamic conquests and inequality in the highly class-based society, in which the wealthy elite and the Magi had amassed a disproportionate amount of wealth that they owed to heavy taxation and the benefactions of the pious.
The play was translated into English by Manuchehr Anvar and published in Tehran.