In the lawless maze of Kowloon Walled City, Xia Liu Yi is one of the fiercest fighters around. To help launder money for his triad boss, he helps produce a film project and forcibly drags He Chu San, a college student, into writing the script. Chu San wants only to escape—but when a set collapses, Liu Yi dives in and shields him in his arms. Their fated encounter begins.