describe some of Amir's most severe injuries

Amir's fight to get back Sohrab is pretty brutal. Assef used his favourite weapon from childhood, his brass knuckles. Assef knocks our Amir's teeth and breaks his ribs, face and nose. Finally Sohrab saves Amir with his slingshot. Ironically this thrashing is a cleansing for Amir. It is a sort of penance for the guilt he has carried around for many years.