Now better known as the Colonial Defense Force (CDF), Perry's service-of-choice has extended its reach into interstellar space to pave the way for human colonization of other planets while fending off marauding aliens. The CDF has a trick up its sleeve that makes enlistment especially enticing for seniors: the promise of restoring their youth.

After bonding with a group of fellow recruits who dub their clique the Old Farts, Perry finds himself in a new body crafted from his original DNA and upgraded for battle, including a brain-implanted computer. But all too quickly the Old Farts are separated, and Perry must fight for his life on various alien-infested battlegrounds.

'Scalzi's astonishingly proficient first novel reads like an original work by the late grand master, Robert A. Heinlein'  Publishers Weekly

'Delivers fast-paced scenes of combat, and pays attention to the science underpinning his premise'  San Francisco Chronicle".