The only survivor of the ill-fated ISA mission is now stranded on Mars. Having been designated a bio-hazard by Earth, any hope of returning home is all but gone. She is alone, isolated, and abandoned. That is, until another human shows up in the main colony airlock. However, he's barely alive and soon dies without regaining consciousness. More disturbing though, a DNA test identifies him as a colonist who has already died, several years earlier...