Kamal's life took an ironic turn for the worse in The Kite Runner after his participation in the attack on Hassan following the kite-flying tournament. Though a somewhat unwilling participant, Kamal was one of the boys who held down Hassan while Assef victimized him. During Baba and Amir's escape from Kabul, they discovered that Kamal and his father were hiding in the same tanker truck. Kamal was virtually unrecognizable: Withered and catatonic, he had no recognition of the scene unfolding around him. Amir overheard only part of the story. Kamal had apparently been attacked by four men (possibly Russian soldiers) and was beaten and victimized--just as Hassan had been. After the tanker truck had finally reached Pakistan, it was discovered that Kamal was dead: He had died from inhaling the fumes inside the tank. Out of grief, Kamal's father siezed a gun and shot himself in the head.
Kamal is Assef’s friend, and they mostly spend time together. Kamal’s first appearance in the story occurs when Assef meets Amir and Hassan as they are walking up the hill to the pomegranate tree. Kamal shares Assef’s disdain for Hazaras, and is always in support of his opinions. Kamal, Wali, and Assef ambush Hassan as he runs after the kite for Amir. They stop him at a deserted alley, and Assef offers to leave Hassan alone if he agrees to hand over the kite. Hassan rejects the offer and stands his ground. After a scuffle, Kamal and Wali hold Hassan down while Assef molests him. The irony of these events is that Kamal suffers the same fate when he is attacked by four men and molested. The events change his life, and he is no longer the Kamal Amir knew from the past, and dies not long after.
Then he told Baba about Kamal. I caught only snippets of it: Should have never let him go alone . . . always so handsome, you know . . . four of them . . . tried to fight . . . God . . . took him . . . bleeding down there his pants . . . doesn’t talk any more . . . just stares . . .