James Potter was leading the battle of Hunter's Square when he was joined by the survivors of John Stafford's unit, as well as Estelle de Winter and Chaz Koonan. After giving the two a crash course in the use of a plasma rifle, he lead them into combat. The battle mostly went in the MTG's favour, before the Enemy lured them into a false sense of security, ambushing them with a number of soldiers bearing portable shields and forcing Potter to make use of one of the unit's few remaining mag grenades.

After evacuating Mythos, Potter joined Joyle Lynch on Grendel's Mother at Adrian Parsons' request. He was charged with taking Elliott Parks to the bridge when Parsons lost patience with the commodore. He later supplied Parks with a plasma pistol to enable the two to repel the Pandoran soldiers that had boarded the ship.

Potter was killed by Anthony Hawke as he and Parks attempted to remove the Tachyon Star Bombs from the carrier.