Yes An underground party refers to a person who works as a secret detective. In ancient times, it was also called diligence, and those who went deep behind enemy lines were called undercover. During the banquet, Wu Bohan was an undercover agent lurking in Chongqing Central Bureau. He helped the protagonist many times. He infiltrated Chongqing Central Bureau through undercover, and provided China with a lot of important information and help. Therefore, Wu Bohan is an underground party in the banquet.