The story is set in Macca, a town surrounded by quicksand. With rumours spreading that the legendary robber Gasback has his sights set on the town, the mayor Kepler has brought together bounty hunters to protect the town. These bounty hunters have been following Gasback from town to town in hopes of bagging the prize. Meryl and Milly have come to town to assess the situation as insurance agents, but are shocked by this turn of events. Moreover, Vash the Stampede is also in town, along with the female bounty hunter Amelia and Nicholas D. Wolfwood.