Instead of keeping his promise, Gushtasp hastened to set his son another task. Rustem was his Pehliva, but it pleased him to send forth Isfendiyar against him, commanding him to bring home the mighty warrior in chains. Isfendiyar pleaded in vain with his father. Then he explained the situation to Rustem, and begged that he would accompany him home in peace to gratify his father. Rustem refused to go in chains, so the two heroes reluctantly began the hardest battle of their lives.
At the end of the first day, Rustem and Rakush were severely wounded, and on his return home Rustem happened to think of the Simurgh. Called by the burning of the feather, the kind bird healed the wounds of the hero and of Rakush, and instructed Rustem how to slay his foe. "Seek thou the tamarisk tree, and make thereof an arrow. Aim at his eye, and there thou canst blind and slay him."
Rustem followed the directions, and laid low the gallant youth. Isfendiyar died exclaiming, "My father has slain me, not thou, Rustem. I die, the victim of my father's hate; do thou keep for me and rear my son!"
Rustem, who had lived so long and accomplished such great deeds, died at last by the hand of his half-brother. This brother, Shugdad, stirred up the king of Kabul, in whose court he was reared, to slay Rustem because he exacted tribute from Kabul.
Rustem was called into Kabul by Shugdad, who claimed that the king mistreated him. When he arrived, the matter was settled amicably, and the brothers set out for a hunt with the king. The hunters were led to a spot where the false king had caused pits to be dug lined with sharp weapons. Rustem, pleased with his kind reception and suspecting no harm, beat Rakush severely when he paused and would go no further. Stung by the blows, the gallant horse sprang forward, and fell into the pit. As he rose from this, he fell into another, until, clambering from the seventh pit, he and Rustem fell swooning with pain.
"False brother!" cried Rustem; "what hast thou done? Was it for thee to slay thy father's son? Exult now; but thou wilt yet suffer for this crime!" Then altering his tone, he said gently: "But give me, I pray thee, my bow and arrows, that I may have it by my side to slay any wild beast that may try to devour me."
Shugdad gave him the bow; and when he saw the gleam in Rustem's eyes, concealed himself behind a tree. But the angry Rustem, grasping the bow with something of his former strength, sent the arrow through tree and man, transfixing both. Then thanking his Creator that he had been given the opportunity to slay his murderer, he breathed his last.