While on a routine supplying operation at the mining colony of High Lonesome on the distant exomoon, LV-422, the supply-ship crew-member, Welles, finds the whereabouts of his hungover and disoriented colleague, Harper, who has been missing for the last twenty-four hours. As they reunite with the unsuspecting colonists, Rolly and Springer, more and more, Harper's condition deteriorates, leading to a bloody encounter with something vicious. Will they survive the endless night shift?