After Lieutenant Gregg informed Darth Vader of Dass Jennir's location on the Colonies planet of Kestavel, Vader told Gregg to inform Gillehspy to prepare the Hound to leave within the hour.
During their mission at Kestavel, after they were getting reports that Vader's soldiers were caught in an engine fuel-laced trap, Gillehspy, observing the battle from the hull of the ship, attempted to get more information from the bridge, although he was forced to drop the subject at blasterpoint by Lieutenant Gregg, who had earlier been ordered by Vader to prevent any of the Imperial forces from interfering with Vader's mission, not even to aid Vader.