The Imperial forces landed on Thyferra, which had been revealed by Imperial intelligence to be Kalast's hiding place. The reconnaissance force secured territory south of a small Rebel installation in the midst of Rebel bacta territory. A field commander led a squad of stormtroopers to sabotage Rebel sensors and communications. Following this, Darth Vader landed and rendezvoused with the Imperial forces. The Imperial Army moved into the northern hills, where they were ambushed by Rebel forces. Clearly, the Rebels still possessed intact sensors that had alerted the base's staff of the Imperial presence.
The lone sensor station was destroyed by the strike team. The Imperial force moved east and destroyed the base's power generator, where they were reinforced by a number of TIE Maulers and Stormtroopers and allowed to use bombing runs executed by TIE/sa bombers. The army moved into the base and wiped out the staff and defense. However, Kalast had escaped due to the field commander's incompetence, and therefore the officer was executed by Vader. Stormtroopers reported to Vader that pirate insignias had been found on Rebel weaponry during their search for survivors. Vader then had the outlying systems monitored, where his search for the pirates aiding the Rebels led him to Ilum.