Buying Time

From Hugo, Nebula and World Fantasy Award winner Joe Haldeman, the bestselling author of "The Forever War" and "Forever Peace", comes a thrilling sci-fi story that examines a world where time truly is money, and what happens when they both run out.
More even than space travel, the Stileman Process has altered twenty-first century life. The most complex of medical miracles, it ensures that every ten years or so, the ailing aging body can be restored to youthful vigour and health. There's a catch, of course: the cost. Every ten years or so you have to come up with £1,000,000 minimum to repeat the procedure or die.
For Dallas Barr, one of the oldest men on earth, it's that time again. While casting around desperately for his next essential £1,000,000, he meets Maria, a woman from - literally - a previous life, and makes two major discoveries.
#1: Not all Stileman 'immortals' were born - or created - the same.
#2: Someone is trying to kill them. All of them.