Garth served the Dominion by piloting a Crucio siege tank, though his primary loyalties were to thor pilot Sandin Forst. Straightforward and obedient, Garth was seen as something of an extension of Forst.
Alongside Forst and SCV pilot Rieff, Garth was dispatched to Mar Sara in order to cleanse the zerg from the planet. Led by Forst, the trio embarked on a different task, namely to gain access to the ruins of the Jacobs Installation and retrieve a cache of ardeon crystals. Reaching the installation, the trio gained access via Forst's firepower. Garth took point, leading his vehicle into the ruins. However, the installation's old but extraordinarily effective security system was still operational. Wall-mounted turrets opened fire on Garth, easily destroying his siege tank and killing him.
Forst did not mourn his loss, thinking he wouldn't have to split any treasure with him.