On the surface, the Thompsons are an all-American nuclear family with an unremarkable—if not happy—home life. However, when a seemingly kind stranger comes into their lives and offers them a vacation, all is not as it seems.
Married with two kids, Larry and Sherry are at the end of their tether with each other in a household that simmers with resentment. When Steve enters their lives, Larry welcomes his new confidant and friend—despite Sherry’s immediate distrust.
As Larry and Steve grow closer together, Steve offers the family his cabin for a make or break vacation to fix their relationship and stop the almost-inevitable divorce from happening.
However, the seemingly idyllic cabin holds a dark secret, one that Larry could never have imagined, even in his worst nightmares. Betrayed by Steve, his entire family is doomed in the team-building exercise from Hell.
As darkness consumes the cabin with a seemingly never-ending onslaught, the family is cast into a life-or-death situation from which there is no escape—worse, they are far from alone.
Unable to trust anyone, and trapped in a situation where one wrong move could wipe the family off the face of the earth, the Thompsons must put aside their differences and fight together—or disappear forever.