Aging looks inevitable, but a growing field of researchers treats it as a biological process that might be slowed, stopped, or even reversed. This BBC and Discovery production follows scientists working to decode the chemical signals that control cell growth and decay, the same signaling pathways that turn a young body into an old one over decades. The film lays out the more radical end of the research too: the search for genes tied directly to aging, and the theoretical possibility of editing them out before birth so the aging process itself never switches on. Rather than settling on one breakthrough, the film surveys the current state of longevity science as a field still arguing with itself over how much of aging is fixed by evolution and how much is just chemistry waiting to be rewritten. It treats death less as a certainty and more as an open engineering problem.