After the Exiles found the Sith people and became their overlords, several of them took the ship they had arrived on and used it to retrace their path to Sith space from the Republic.
They took with them several Massassi warriors, weapons and their new found secrets in Sith alchemy in an attempt to destroy the Jedi against the orders and will of their leader, Dark Lord of the Sith Ajunta Pall.
The battle resulted in their destruction and the Jedi learning of Sith space. After the Jedi attacked the Sith. Pall would later use the story as a lesson against too much ambition.