In 1942, Su Yao, the female caravan leader, was entrusted by the underground party to escort US military radio parts along the Burma Highway. On the way, they met "businessmen" disguised as Japanese military agents and were robbed by bandits. Su Yao relied on the "escort skills" of the caravan to resolve the crisis, but found out that the US military liaison officer was a traitor. In the end, Su Yao cooperated with Xiao Zhan, a soldier from the expeditionary force who arrived, and intercepted the parts under the Nujiang Bridge and sent them to the front line.
