Following the events of The Four II, Emotionless has left Six Doors, as has Cold Blood on his own. The departure of two of the four constables has effectively left Six Doors defunct. At this time, trouble begins to brew in the Imperial Palace as Emperor Huizong plans to travel incognito to the outside world. When he is almost assassinated and subsequently disappears, Cold Blood, Emotionless, Iron Hands and Life Snatcher must band together once again under Master Zhuge to save the empire from a massive conspiracy.