Soon thereafter, intelligence reports indicated that An's forward commander Cui Qianyou (崔乾祐) had weak forces outside the Tong Pass, and Emperor Xuanzong and Yang Guozhong became convinced that it was the time to counterattack to recapture the eastern capital Luoyang -- despite repeated petitions by Geshu that it was inadvisable, agreed with by Guo Ziyi and Li Guangbi, who were then attacking An's holdings north of the Yellow River and believed that the proper strategy was for Geshu to hold Tong Pass and for them to destroy An's power base first. Yang Guozhong, in particular, was concerned that Geshu was intending to attack him instead, and therefore had Emperor Xuanzong issue repeated edicts ordering Geshu to engage Cui. Geshu was forced to do so, and once he engaged Cui's troops, he fell into a trap Cui set, and most of the Tang army was wiped out. Geshu was only able to gather 8,000 soldiers to return to Tong Pass. He prepared to defend it anyway, but his subordinate Huoba Guiren, believing the situation to be hopeless, tried to convince him to surrender to Cui, pointing out that he was putting himself in the same position as Gao Xianzhi. Despite Geshu's protestations that he would rather be like Gao than to surrender, Huoba bound him to a horse and then took him to surrender to Cui.
Reading Geshu Han's biography he seemed like a paragon of loyalty aside from one instance where he participated in palace intrigue. At the end he said he would rather die than surrender and surveying his career you would be inclined to believe him. However, once delivered to An Lushan he submits and offers to write letters to other Tang officials to get them to surrender to An Lushan...
I read the bio at wikipedia: http://en.wikipedia.org/wiki/Geshu_Han
I wondered if it is accurate as his actions at the end seemed like a real twist in the tale.