The Widowmaker Unleashed — Mike Resnick

He was the most feared bounty hunter in the galaxy, the consummate killing machine, a man known only as the Widowmaker. Now, after a century of being cryogenically frozen, Jefferson Nighthawk has a new lease on life--and new enemies who want him dead....

Jefferson Nighthawk has been awakened from his frozen sleep, his deadly disease cured. But although he still has the experience and instincts of the legendary Widowmaker, Nighthawk is now biologically in his sixties. His reflexes slowed by age, looking only to live out his days in peace, he decides on a quiet retirement on a Frontier world.

Easier said than done. For while Nighthawk lay in cryogenic sleep, his two clones were killing in his name, leaving a trail of vengeful enemies in their wake, Nighthawk has one advantage: no one knows who he is just yet. But once word gets out that he's back, every assassin on the Frontier will be out to make a rep by gunning him down. Suddenly the Widowmaker has only two choices: pick up his weapons ... or face death again--and this time for keeps.