Girding his sword-belt tighter than ever before, Rostam mounted the scarlet Rakhsh and galloped toward the Seven Mountains, where the formidable demon hosts of Mazandaran had massed. Approaching a bottomless, pitch-black cavern guarded by a ring of sorcerous armies, Rostam turned to Avlad and said, 'Everything you foresaw has proven true. Now the moment of battle is at hand; reveal the path and unlock the secrets of this abyss.' Avlad replied, 'When the sun reaches its zenith and the heat scorches the earth, a spell of deep slumber overcomes the demon realm. None shall stay awake save for a few sorcerer guards. If the Almighty Creator grants you His grace, that is the hour of your victory.'
Rostam waited patiently until high noon bathed the heavens in fiery gold. Binding Avlad securely with his lasso, he swung into his saddle, unsheathed his dragon-slaying blade, and roared like thunder, calling out his legendary name. He plunged into the demon legions like a raging whirlpool, cleaving the heads of their chieftains from their shoulders. Overwhelmed by the terrifying fury of the Iranian champion, the demon ranks broke and scattered into the hills.
Radiant as the sun, Rostam approached the gaping maw of the cavern—a dark abyss resembling the gates of Hell, where the White Demon's massive form lay hidden in absolute gloom. Standing blade in hand, the hero paused; his eyes could perceive nothing in the suffocating darkness, and there was no room for retreat. Rubbing his eyes until they adjusted to the shadows, he caught sight of a mountain-like creature sleeping: its skin pitch-black, its hair as white as a winter lion, its immense body filling the vast cavern.
Sensing the intruder, the White Demon surged upward like a black peak clad in iron gauntlets and a dark helm. A transient chill gripped the champion's heart, for the battleground was narrow and fraught with danger. Yet Rostam roared like an enraged elephant and swung his razor sword with divine force, severing one of the demon's legs at the thigh. Crippled yet demonic in strength, the White Demon locked horns with the hero; the two titans wrestled in the gloom, tearing flesh from bone until the cavern floor turned into a mire of crimson blood. Both knew that surviving this hour meant living forever.
Summoning the strength bestowed by Yazdan, Rostam gripped the mountain of flesh, hoisted the demonic king above his neck, and hurled him down onto the stone floor with crushing thunder. Before the beast could rise, Rostam plunged his dagger into its breast, tearing out its heart and dark liver. The monster gasped its last, and its dark soul departed into eternal darkness.
Emerging from the bloody cave, Rostam untied Avlad and handed him the demon's heart and liver. Reminded of the hero's promise to grant him the sovereignty of Mazandaran, Avlad sought assurance. Rostam affirmed, 'My word is unbroken. But first I must unseat the King of Mazandaran and vanquish his remaining sorcerers; then the realm shall be yours.'
They hastened to King Kay Kavus and the captive Iranian lords, whose eyes had been struck blind by demon magic. Announcing the demise of the White Demon, Rostam dropped the warm blood of the demon's liver into their clouded eyes. Instantly, the dark scales fell away, and their sight was restored to radiant clarity. Kay Kavus ascended the ivory throne, hung his crown overhead, and spent seven days feasting in victory with Rostam and the great paladins—Tus, Fariburz, Gudarz, Giv, Raham, Gurgin, and Farhad. On the eighth day, the Iranian host rode forth to cleanse the demon land, laying waste to their strongholds until retributive justice was fulfilled, whereupon Kavus called a halt to the slaughter and dispatched a stern ultimatum to the stubborn King of Mazandaran.