A group of crime scene cleaners struggle to escape a murder house after becoming trapped by an ancient Nordic demon that is hell-bent on driving them insane.

Barbara finds her last hope to be a grandmother when her son, Ethan, falls for Kendall, a divorcee with children. At first kept at arm's length, Barbara quickly infiltrates the family by using devious tactics to win over Kendall's kids. Unannounced visits escalate to murder as Barbara will do anything to protect her relationship with her grandchildren. With her life in danger, Kendall must outsmart her mother-in-law to save her children and expose Barbara for who she really is.