Blood Moon

Executives running the last outposts of humanity are going missing. Decades ago, certain cities lifted off from the surface of Earth, protected by fusion-powered shields. Their destination was the moon, to mine the needed resources to make the next phase of the journey. The culture in these city-colonies has separated into two - the "royals" and the "down-belows". Now someone is carefully reducing the royal houses, one by one. Who that someone or someones are, or how they are doing this is unknown. But, not unwatched. The question is whether the watchers can solve the mystery in time. And, do something effective to stop the disappearances. Before these city-colonies, and their hopes for rescuing humanity, die.