Fact1: samples point to life on planet, Fact2: Crewmate Richard Harrington drives Petrovic in solar powered rover to spot, Fact3: team return with equipment, Fact4: Rebecca Lane is stabbed in leg during frantic escape to rover, Fact5: other rover is at site of fissure
Output: In the 2040s, a Martian research base, Tantalus Base outpost, is created. The eight person crew, who have been stationed there for six months, are only nineteen hours from the completion of their research mission. The spacecraft Aurora is inbound from Earth and will collect the team by lander. Mars scientist Marko Petrovic has found samples that may point to life on the planet. Without revealing his discovery, he devises a ruse for a last sojourn on the surface. Crewmate Richard Harrington drives Petrovic in a solar powered rover to the spot where he had found the sample. After he obtains soil with the biological agent present, a fissure swallows Petrovic. Captain Charles Brunel and crewmate Lauren Dalby plan to explore the pit to retrieve Petrovics body. Dalby remains at the pit but disappears before the team can return with equipment. Brunel authorizes Vincent Campbell to explore the pit and he finds a funguslike life that grows in the fissure. Dalby and Petrovic reappear at the main outpost, but the Martian bacteria has mutated them into fast, aggressive, zombielike creatures with blackened skin and no trace of their original personalities. Harrington dies from a power drill attack by one of the zombies and later revives as one himself. The remaining crew hold off the zombies while Brunel and Campbell return. Brunel is also fatally injured and reanimates, which provides the crew with new insight into the symptoms: thirst, memory loss and aggression. Eventually, after several fights and escapes from the zombies through the habitat modules, mission psychologist Robert Irwin deserts scientist Kim Aldrich, who had often infuriated her crewmates. Rebecca Lane is also stabbed in the leg during the frantic escape to a rover. With their rovers power low, the survivors – Campbell, Irwin and Lane – decide they must get to the other rover, which is still at the site of the fissure. Under the pretense of a scouting operation, Irwin steals the second rover and unsuccessfully attempts to persuade Campbell to abandon Lane, who he states is infected. Irwin meanwhile conceals evidence of his possible infection. While Campbell and Lane wait for the sun to rise and the solar powered batteries to recharge, they discuss the nature of the zombies and Lane questions whether any human consciousness remains trapped in them. Campbell attempts to comfort her and falls asleep. When he wakes up alone, Campbell realizes that Lane has fled into the desert and he chases her. Lane, who knows she is likely to turn, fails to deter Campbell from following her and in desperation, commits suicide by removing her helmet. After she dies, Lane reanimates and begs Campbell to destroy her. Campbell reluctantly complies by bashing her head in with a rock. Campbell and Irwin separately converge on the Aurora lander, where the reanimated Aldrich kills the landers crew. The other zombies appear desiccated and inert. An obviously infected Irwin initiates a launch, which takes him and Campbell into orbit. Campbell stuns Irwin and ejects the body and virulent blood droplets into the vacuum of space. In a message to mission control, Campbell says he does not have enough fuel for a rendezvous but supplies aboard can last for months if they want to launch a rescue. He tells them that this may not be advisable as he may be infected; if so he has just enough fuel for reentry and a fast death. Campbell concludes that it will take 15 minutes for the transmission to be received and will be awaiting their reply. He subsequently ends the communication, still floating alone in space.