Alien Base

Alien Base is a 1981 role-playing game adventure for "Space Opera" published by Fantasy Games Unlimited.
Contents.
"Alien Base" is an adventure involving a search by the player characters for the missing survey ship "Timothy", which takes them to the barely surveyed planet Thonne, where they learn that the natives have been invaded by alien Slavers who now seem to have sinister plans for the human race.
Reception.
William A. Barton reviewed "Alien Base" in "The Space Gamer" No. 48. Barton commented that ""Alien Base" [is] a relatively complete and satisfying adventure for "SO", either as a stand-alone scenario or as the first in a planned series. If you enjoy "Space Opera", I recommend "Alien Base"."