Gungrave first approaches its stages as a series of missions issued by Dr. T, first to gather information on the current makeup of Millennion from a low-level street gang, and next destroying a research facility that creates Harry's undead soldiers. In the third stage, while attempting to pump information from an informant, Grave comes into contact with the leadership of the Millenion organization—once friends and allies that he now faces as enemies. Each have used the research Harry supported to give themselves inhuman powers. From here on, Grave is hounded by each member as he makes his way to Harry's tower at the heart of the city.