I think that the significance of the fortune teller memory is to reflect how so little is clear at this moment. In an odd way, Amir's recollection of the fortune teller is about as clear as Hassan's understanding of what happened to him and why there was no help. The fortune teller in the dream does not reveal much in way of good to Hassan. In the rape that follows, there is murkiness and a sense of absolute emotional chaos. The fortune teller, representative of someone who can see into the future and provide some level of clarity to that which is unknown, is unable to do so. This helps to feed the emotional chaos endured at this moment by both Hassan and Amir. At the same time, the narrative style of the chapter is also disjointed, cutting in and out from memory to the rape. The fortune teller's lack of clarity helps to bring out the exact emotional timbre of the scene. In doing so, the fortune teller represents how little sense can be made of what happens to Hassan. The only clear element that emerges is that Amir had the chance to do something and didn't. This could also amplify the reaction that the fortune teller had, a vision that conveys how so much went wrong and how Amir is compelled to "become good again."