Uninvited and unwelcomed, Dan's estranged mother Margo shows up at his doorstep moments before a freak snowstorm hits their small Texas town. The arctic storm comes fast and hard, trapping Dan and his wife, their teen daughter, and her boyfriend inside with the malicious old woman who seems hell-bent on destroying everything her son and daughter-in-law have built together. Long-buried family secrets are exhumed, causing tensions to flare and tempers to erupt. As anger consumes the household and things spiral out of control, inside is Hell. But outside within the snow is something far more sinister. Something full of rage. Something violent. Something with a craving for brutality.