[Source] A holocron created by the Sith Lord Tulak Hord was one of a set of five Sith artifacts that he used to conquer the Dromund system. When Tulak Hord turned on his ally Aloysius Kallig, Kallig managed to steal the holocron from Hord before his death, and it was stored in the Dark Temple on Dromund Kaas. Thousands of years later, Kallig's descendant retrieved the artifact from the temple, and Darth Zash tried to use it to recreate Hord's ritual.