23rd-century Earth is a good place to be: after an atypically friendly first contact with an alien species, the planet's ills have been cured and peace reigns supreme. But some will always resist change, let alone utopian ideas. One such organization was the innocently-named American Neutral Investigators, and its leader Mapier was exiled off-planet for disturbing the peace. This decision did not prove far-sighted however; Mapier worked diligently, pirating and destroying, harvesting debris, alien technology and raw materials, and gradually built up a huge armed space fortress from which the ANI continue to terrorize known space.

This is where the player comes in, piloting an infiltrator ship into the bowels of the ANI's Mapierian Anti-Complex (ANIMAC) to find and destroy the central command. The meandering tunnels burrowing through the planet-sized base consist of hundreds of different rooms, littered with automated defenses, mines and hostile drones, while the Infiltrator only packs a single forward-firing photon launcher. Bridges and invisible warps complicate matters further, as does the security system which makes backtracking a deadly risk.