Emma Watson a research physician has been training for the mission of a lifetime: to study living organisms in the microgravity of space. But the true and lethal nature of the experiment has not been revealed to NASA and once aboard the space station things start to go wrong. A culture of single-celled Archaeons, gathered from the deep sea, begin to rapidly multiply and infect the crew - with deadly and agonising results. As her estranged husband and ground crew at NASA work against the clock to launch a rescue Emma stuggles to contain the lethal microbe. But with the contagion threatening Earth's population, there are those who would leave the astronauts stranded in orbit, quarantined aboard the station.