Teacake (Joe Keery) and Naomi (Georgina Campbell), two young employees of a self-storage company built on the site of an old US military base, have their wildest night shift ever when a deadly parasitic fungus escapes from hibernation in the lowest sublevel of the base. As the temperature rises underground, this highly contagious microorganism multiplies and unleashes its terrors on the facility's inhabitants – human and otherwise. With time running out, it's down to Teacake and Naomi, with the help of a grizzled bioterror operative (Liam Neeson), to contain the rapidly mutating menace and prevent the explosive extinction of mankind itself. From the producer of Zombieland and the screenwriter of Jurassic Park.