The plot is linear and is mostly provided for the introductory and concluding full-motion video cutscenes. After the "Material Defender" (voiced by George DelHoyo) has destroyed all of the Solar System's mines in the original game, he stops in the asteroid belt to dock. He is then contacted by Post-Terran Mining Corporation executive Dravis, who exploits a loophole in a contract to coerce him to accept a new mission or forfeit his reward and face legal action. The Material Defender consents, and as Dravis tries to convince him that he is merely embarking on a reconnaissance mission, his ship is fitted with a prototype warp core. He is then sent to clear out PTMC's deep space mines beyond the Solar System.

The Material Defender teleports to Zeta Aquilae and five other, fictional star systems and destroys their mines. In the sixth system, the last mine seems to run all through a planetoid, which is revealed in the final cutscene to be a large spaceship. After the spaceship breaks apart, the Material Defender alerts Dravis to his return home, but his warp drive malfunctions and he teleports to an unknown location. The camera then fades to that location and the ship appears, heavily damaged and crackling with excess radiation drifting towards the camera, ending with the words "to be continued..." being displayed.