The inequality between the colonies and Earth foments rebellion. In 2802 there are two guerilla movements on Mars, one that concentrates on destroying and capturing Imperial infrastructure and supplies and another bent on killing Imperial personnel and sympathizers. Both groups operate from underground bases and make do with modified mining HERCs and tanks. The rebels partially offset their disadvantages with superior weapons taken from the alien "Tharsis Cache"; an underground stockpile of alien technology discovered by rebels while digging new tunnels. Eventually the rebellion becomes too great for the police to contain and the Knights are deployed to Mars to crush the insurrection.