In the year 1941 when Hong Kong was occupied by Japan, a Communist agent disguised as a military officer receives an important mission that is critical to the success of the revolution. Ye Chong is a nationalistic young man with Communistic ideals. He comes to Hong Kong to help Sato build the presence of the Japanese military police in the area. In truth, he has sworn allegiance to his country long ago and secretly operates under the codename autumn cicada to relay Japanese intelligence to his comrades. His position puts him at risk time and again for the sake of his countrymen.