Sothis III

From Memory Alpha, the free Star Trek reference

Sothis III is the home planet to the Satarrans, a humanoid civilization who allegedly hate mysteries and are not as technologically advanced as the Federation. They possess a unique device which allows them to wipe the collective memory of the entire crew of a starship. They also possess the capability to impersonate other humanoid appearances. By 2368, the Satarrans had been at war with the Lysians for decades. (TNG: "Conundrum", "The Chase")