In 1942 in North China, villager Chen Fan worked as an underground traffic officer, delivering medicine to the base area and spreading news about the Japanese army's "mopping up" operations in the name of "visiting relatives." Once while delivering medicine, he was inspected by the Japanese army. He hid the medicine in the mezzanine of the diesel truck and helped the injured liaison officer avoid the search. When the Japanese army launched a large-scale sweep, Chen Fan led the people in the base area to hide in "underground cave dwellings" and relied on tunnel warfare to delay the attack until the Eighth Route Army reinforced the situation.
