Wrench served as an Advanced Recon Commando. He belonged to a unit of clone troopers stranded on Pengalan IV after their LAAT/i went down during a large-scale Republic withdrawal.
Along with his fellow clone soldiers and a Republic financial officer called Joram Kithe, they were left to their own devices to find a way to leave the desert planet. Kithe, upon waking up, revealed his commission as a Republic Intelligence lieutenant and assumed leadership.
Kithe found the troopers' adherence to protocol unsettling, and he sought to encourage independent thinking. To achieve this, he assigned nicknames to the troopers. Wrench received his name due to his superior mechanical aptitude compared to the others.
After arriving at Tur Lorkin, the closest settlement, and infiltrating a starship hangar, Tooth and Kithe discovered that the village was actually the location of the diamond boron missile production plant, not the factory where the earlier ambush had occurred.
Intent on its destruction, Tooth confronted Kithe, ready to disobey his directives to finish the objective. Impressed by this, Kithe gave in. The troopers, assisted by Kithe, sabotaged the manufacturing plant, while Tooth commandeered a Corellian vessel to lure CIS fighters away from the starship hangar, allowing Joram and the remaining troopers to get away. During the factory raid, Wrench took charge of a missile cache, utilizing them to obliterate the facility.
He made it through the mission, and would continue his service alongside the other survivors.