Iron Monkey teams up with his blind friend Jin to bring underworld agent the Tiger to justice. When Jin's son arrives he soon becomes caught up in the conflict, leading to Jin's death. Jin's son now joins the Iron Monkey to avenge his father's memory, as they launch an attack on the Tiger's lair.
In 1937, after the Marco Polo Bridge Incident, the Second Sino-Japanese War breaks out. San Mao, a wandering orphan, joins the army to participate in the Battle of Shanghai.
