The game begins when Wheeler embarks on a reconnaissance mission to Mars' inner moon, Phobos, to monitor the movements of the L.E.D.s, a ruthlessly hostile alien species who have ransacked the colony. The expectation is that everyone is dead. Upon arrival, Wheeler picks up a distress call from Cimmeria Rajan, Red Rock's young and beautiful Chief Colony Officer. Contrary to the military's worst fears, she and a handful of others survived the alien invasion. Wheeler quickly descends to the planet's surface for a sustained rescue operation that challenges him to swim through underground waterways, cross Mars' frozen deserts, penetrate the colony ruins, and sneak into alien ships, battling L.E.D.s at every turn.