From the wreckage of a research facility in Switzerland, a plume of toxic smoke and ash pours into the sky, forming an impenetrable cloud that is slowly smothering the world in darkness. As Europe disappears beneath the Cloud, a squad of United States marines are sent on a desperate mission to find out what went wrong, and how to undo it before it's too late. Venturing into a cold, dark world, the marines must travel deep under the Cloud, with no...