Machika Balfaltin inherits the one bounty her grandfather Zol never collected: kill the immortal known as Methuselah. What she finds instead is Rain Jewlitt, a gentle, scatterbrained man who has lived more than six centuries and lost more than he can carry. Unable to go through with it, Machika stays at his side while he waits for Yuca, the person tied to his immortality, as rival bounty hunters and a secretive organization close in on them both.