The Malachor III Expedition was a Mission undertaken by the Jedi Order around the time of the Great Galactic War on the dead Sith Planet of Malachor III in hoping to found ancients sith secrets. Unfortunately, the Jedi underestimated the dangers of the place and sent only six Padawans, Parkanas Tark, Yuon Par, Duras Fain, Sidonie Garen, Eriz Vossan and Cin Tykan. Their arrival awakened the dark spirit of the dead Sith Lord of the resurgent Sith Empire Terrak Morrhage. Morrhage's spirit played with the emotions of the young Jedi and drove them insane. While the rest of the team managed to escape the planet, Tark was left behind to be tortured by Morrhage and, eventually, Morrhage's dark spirit corrupted and possessed him.
Star Wars: The Old Republic (First mentioned)