Buck's adventures take place in a future where humanity has joined an interstellar coalition known as the . Human colonization and exploitation has resulted in the development of various human and mutant sub-species, as well as methods such as terraforming (altering marginally habitable worlds into environments where humans can thrive) and pantropy (genetically altering humans to thrive on marginally habitable worlds). Humanity has also become the custodian of The Winslow, an immortal, indestructible, sentient small fuzzy alligator-like creature that usually doesn't do anything more than say "Hi!", and is highly sought after by other species for various reasons.