Since the 1960s, a disproportionate number of the population in and around Nome, Alaska, have gone missing. Despite FBI investigations, the disappearances remain a mystery. Dr. Abigail Tyler, a psychologist, may be on the verge of blowing the unsolved cases wide open when, during the course of treating her patients, she finds evidence of alien abductions.

A team of space marines known as the Rapid Response Tactical Squad, led by Sarge, is sent to a science facility on Mars after somebody reports a security breach. There, they learn that the alert came after a test subject, a mass murderer purposefully injected with alien DNA, broke free and began killing people. Dr. Grimm, who is related to team member Reaper, informs them all that the chromosome can mutate humans into monsters — and is highly infectious.