Unit 4 is a soft-shelled organic maintenance robot tasked with overseeing a mine on Jupiter. However, it has inexplicably missing data files, and when its handler orders it to defend against alien invaders, Unit 4 begins to question its programming. Activation Degradation by Marina J. Lostetter is a compelling space thriller that questions what makes humans human and what sort of rights do non-human sentient beings deserve. I think what I enjoyed most about this book is seeing Unit 4’s inner conflict and natural progression from more cerebral robot to a robot with very human emotions. It’s a charming, sympathetic character who likes bees and cats, so I couldn’t help but root for the robot. I admit, my first experience with Lostetter was through The Helm of Midnight , and while both books are introspective and emotionally-driven, I find this story has better focus and is more tightly written. At no point did it feel like a slog to get through. Overall, this is a high-octane A...