Light chaser

Hamilton (the Greg Mandel series) and Powell (the Embers of War series) create an intriguing story of forgotten love and two people's attempt to save humanity. As a human enhanced with eight-letter DNA, Amahle's lifespan was already increased; as the captain of the Mnemosyne, forever traveling between the planets of The Domain at close to the speed of light, the time compression has made her virtually immortal. Amahle's job is to collect and distribute memory collars to the populace. Passed down for generations, the collars record the experiences of their wearers. Amahle spends much of her time immersed in these recordings--which is how she comes across a 1,000-year-old message from someone named Carloman telling her not to trust the AI on her ship. Amahle follows clues to a trail of further messages from Carloman spanning planets and lifetimes. Through these missives, she comes to understand a disturbing truth about The Domain, the powers controlling it, and Carloman's plan to save its inhabitants. Though the pace is slow, the authors' engagement with both hypothetical science and reincarnation will hold readers' interest, and the worldbuilding hints at a vast, fascinating universe. This short but expansive narrative offers plenty to please sci-fi fans. (Aug.)