An Inheritance of Stars
It is no secret that before the arrival of humans, the Argylian Expanse sheltered alien life. There are even some few worlds still populated or co-inhabited by various non-human sentient beings today.
Many evidence has been documented about various cultures which either traveled through, or at one point resided within the Argylian Expanse. Other alien races occasionally enter the Expanse by way of Port Wander, in order to trade with and study human life. However due to events in the past, these ships are only admitted in small numbers, and subjected to rigorous scrutiny. After all, the Great Enemy of legend was never identified or known.