When Micajah Fenton discovers a crater in his front yard with a broken time glider in the bottom and a naked, virtual woman on his lawn, he delays his plans to kill himself. While helping repair the marooned time traveler's glider, Cager realizes it can return him to his past to correct a mistake that had haunted him his whole life. In gratitude for his help, the virtual creature living in the circuitry of the marooned glider, sends Cager back in time as his ten-year-old self, knowing everything he'd known at eighty. As a bonus, it also gives him access to advanced equations of space and time.But living life over knowing the future isn't as easy as Cager anticipated, and he bungles his chance at correcting the most serious mistake of his life. Now he must use his new knowledge of advanced math to build his own time machine to go back and try again. Meanwhile Cager's repairs to the creature's glider fail, keeping it stranded near earth. In desperation, the whale-like creature sends, Ell, a near-human, female copy containing it's consciousness to help Cager. While perfecting time travel, Cager and Ell overcome enormous problems, even being hunted by dinosaurs in the Cretaceous, and Cager falls in love with this indomitable anthropomorphic copy of a creature from across the galaxy.