As the first manned mission to Mars nears its end, the crew of the Tantalus Base is eager to return home after six grueling months on the Red Planet. The atmosphere among the eight astronauts, led by seasoned commander Charles Brunel, is tense with anticipation and fatigue. Scientist Marko Petrovic believes he has made an astonishing discovery—evidence of bacterial life on Mars. However, as the team prepares to evacuate, a routine excavation turns disastrous. An unforeseen accident leaves crew member Marko presumed dead, and his body is lost in the chaos, further distressing the already weary team trying to secure their research and themselves before departure.

In the aftermath of the accident, the mood at the base shifts to one of anxiety and sorrow. Crewmember Vincent Campbell is particularly affected by the tragic turn of events, struggling to maintain his composure. Amidst the desire to honor their deceased colleague and the pragmatic need to leave Mars before their window closes, a routine check reveals an unsettling incident at the site of Marko's disappearance. The crew is forced to confront the possibility that Marko's death might not be what it seems, and they quickly find themselves entangled in a terrifying situation that threatens not just the success of the mission, but their very lives. Bound by the unwavering isolation of the Martian landscape, the crew must navigate a path between personal turmoil and collective survival.