Final answer:
Amir frames Hassan for theft by placing a watch and money under his mattress in 'The Kite Runner', which has significant consequences for their relationship and the novel's plot.
Step-by-step explanation:
In Khaled Hosseini's novel The Kite Runner, Amir plants a watch and some money under Hassan's mattress in order to frame him for theft. This act is born out of Amir's complex feelings of guilt, jealousy, and the desire for his father's attention.
Amir's betrayal of his loyal friend leads to a pivotal moment in the novel, with repercussions for both characters that unfold throughout the rest of the story.