In the game's back-story, a species of powerful, unknown extraterrestrials enters the Milky Way with the intention of enslaving its inhabitants.
type species | introduced species | endangered species | Endangered Species Act | On the Origin of Species | fictional universe | Introduced species | List of Uplift Universe species | Xuanzang (fictional character) | vulnerable species | Fictional crossover | Endangered Species | Endangered species | Vulnerable species | Threatened species | threatened species | X-Men: Endangered Species | International Institute for Species Exploration | fictional crossover | UNESCO Intangible Cultural Heritage Lists | Type species | Psychohistory (fictional) | psychohistory (fictional) | Parker (fictional criminal) | North Western Railway (fictional)#Thomas' Branch Line | List of protected species in Hong Kong | List of Euphorbia species | Grayling (species) | Athos (fictional character) | Wonderland (fictional country) |