King Kay Kavus had, against everyone’s advice, marched into the land of Mazandaran, ruled by demons. The White Demon blinded him and his army and took them prisoner. Only Rostam could save him. To get there quickly he chose the shortest but most dangerous route, on which seven labours (Haft Khan) awaited him.
On the first night his loyal horse Rakhsh killed a lion while Rostam slept. Then he nearly died of thirst in the desert until a ram led him to a spring. On the third night Rakhsh twice woke him because of an invisible dragon; the third time Rostam saw it and killed it with Rakhsh’s help. Next he met a beautiful woman who offered him wine; when he spoke the name of God she showed her true face as a witch, and he killed her.
In the fifth labour he captured the border guard Olad, who then showed him the way. In the sixth he defeated the demon lord Arzhang. The seventh led him into the cave of the White Demon, whom he killed after a terrible fight. He dripped the blood from the demon’s liver into the eyes of Kay Kavus and the warriors, and they could see again. To this day Haft Khan means a series of hard trials in Persian.