The Alliance to Restore the Republic, during an investigations about the loss of starships in the Métensis system, found Kalonn. From space, it appeared to be a hollow planet with a high concentration of metallic components. A team then explored the surface and the ship, only to discover hints of battle.
The droid introduced itself as "Kalonn, the 102nd Exterminator", and told the Rebels that it was awakened by the crashed ships. Now conscious and willing to finish its mission, Kalonn started its propulsion, but was stopped when the exploration team destroyed its primary energy source.