After a Black Friday riot ends in tragedy, a mysterious Thanksgiving-inspired killer terrorizes Plymouth, Massachusetts - the birthplace of the holiday. Picking off residents one by one, what begins as random revenge killings are soon revealed to be part of a larger, sinister holiday plan "Thanksgiving".

A younger household, "The Family" residing in isolation and compelled into onerous labor out of worry of dishonoring their Father and Mom, struggle to free themselves from their non secular cult.