Team Omega just went through hell to find their prey, the madman Simon Haddo, only to have him escape at the last moment. These mercs didn't just do battle with a Mecha-Satan for nothing, so are determined to bring Haddo down and get paid for their efforts. They follow him, with the help of their enigmatic android guide, to the planet Mercury and a fortress factory known only as Purgatory, where they must face yet another gruesomely engineered...