Soon thereafter, intelligence reports indicated that An's forward commander Cui Qianyou () 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. Cui Qianyou delivered Geshu Han and Huoba Guiren to Luoyang, which An Lushan had made the capital of his new state of Yan after claiming imperial title. An executed Huoba for his treacherousness, and asked Geshu how he felt now, after having slighted An for years. Geshu responded that he simply did not see An's greatness at that time, and offered to write letters to Li Guangbi, Lai Tian, and Lu Gui, to ask them to surrender to An. An was pleased, and gave Geshu the titles of "Sikong" (司空, one of the Three Excellencies) and "Tong Zhongshu Menxia Pingzhangshi". Soon, however, those subordinates to whom Geshu wrote replied, rebuking him for his failure to die for Tang. An realized that Geshu was of no use to him, and put him under arrest. In spring 757, An Lushan was assassinated by his son An Qingxu, who took the throne subsequently.