Thirteen

In Thirteen, Richard K. Morgan radically reshapes and recharges science fiction yet again, with a new and unforgettable hero in Carl Marsalis: hybrid, hired gun, and a man without a country . . . or a planet.
Marsalis is one of a new breed. Literally. Genetically engineered by the U.S. government to embody the naked aggression and primal survival skills that centuries of civilization have erased from humankind, Thirteens were intended to be the ultimate military fighting force. The project was scuttled, however, when a fearful public branded the supersoldiers dangerous mutants, dooming the Thirteens to forced exile on Earth's distant, desolate Mars colony. But Marsalis found a way to slip back-and into a lucrative living as a bounty hunter and hit man before a police sting landed him in prison-a fate worse than Mars, and much more dangerous.
Luckily, his "enhanced" life also seems to be a charmed one. A new chance at freedom beckons, courtesy of the government. All Marsalis has to do is use his superior skills to bring in another fugitive. But this one is no common criminal. He's another Thirteen-one who's already shanghaied a space shuttle, butchered its crew, and left a trail of bodies in his wake on a bloody cross-country spree. And like his pursuer, he was bred to fight to the death. Still, there's no question Marsalis will take the job. Though it will draw him deep into violence, treachery, corruption, and painful confrontation with himself, anything is better than remaining a prisoner. The real question is: can he remain sane-and alive-long enough to succeed?