A team of super-skilled criminals roams a science-fiction Wild West, each with their own reason to hunt for the ultimate prize: the 12 Rings of the Dead, which can raise the dead and grant eternal life.

Somewhere in the desert lies the world's greatest treasure: the 12 Rings of the Dead, the only source of the mysterious substance Zombie Powder, which can raise the dead and grant eternal life. Into this world stalks Gamma Akutabi, a man with a metal arm and a six-foot chainsaw, cybernetically enhanced master of the legendary martial art . But it takes more than one man to find the ultimate prize. You need a team: super-gunman C.T. Smith, knife-slinging teenager Elwood, and brilliant (and impossibly big-breasted) journalist Wolfgangina. Against an army of crooks and killers, against runaway trains and superpowered madmen, they'll need all their skills...but the most dangerous thing in the west might be the Rings themselves... All volumes except the first also contain a bonus short story by Tite Kubo: Ultra Unholy Hearted Machine (vol. 2), Rune Master Urara (vol. 3), and Bad Shield United (vol. 4).

When the prize is a Ring of the Dead, murder is a small price to pay! Stealing the comatose body of Wolfina's brother (and the Ring buried inside it), Balmunk the mystic lures our heroes to his deadly circus, where fire-breathers and knife-throwers await them. Has master swordsman Gamma Akutabi finally met a foe worthy of his skills? As the circus train races across the desert, Wolfina struggles to free her brother's body before it becomes an ingredient in Balmunk's recipe for immortality. But the ride isn't over yet... Volume 3 also includes a special bonus story, "Rune Master Urara"!