In 44 BC he was reported to be on the north slope of the Tian Shan in modern Xinjiang. The Han court returned his hostage son. For unknown reasons, Zhizhi murdered the envoy who accompanied his son. He made a marriage alliance with the rulers of Kangju near Lake Balkhash and led his entire tribe westward. They suffered greatly from cold and only 3,000 people reached Kangju (it is not clear if this was the whole population or counts only fighting men).