Zelka Forn was an elderly Human male doctor who was running a clinic in a part of the Upper City on the planet Taris by the year 3956 BBY. Forn would not refuse help to anyone, regardless of social or xenophobic reasons that would cause others to turn them away. When Revan, a soldier in service to the Galactic Republic, arrived on Taris after his ship, the Endar Spire, was destroyed following a Sith attack, Forn asked him for assistance in procuring a serum for the Rakghoul plague, a disease that transformed those infected into rakghouls—violent, deformed mutants. Revan journeyed into the Undercity of Taris and found the corpse of a Sith soldier who was carrying the rakghoul serum. Despite a large offer of credits from Gurney, Forn's own assistant, if Revan gave the serum to the crime lord