On Thanksgiving night, twin brothers Todd and Terry sneak out of the family's car at a drive-in theatre while their mother Maddy is distracted. Terry brutally murders a man and frames Todd for it. Traumatized, Todd is sent to a mental institution, where he remains for several years, while Terry grows up seemingly well-adjusted and living with their mother. As Thanksgiving approaches again, Todd escapes from the institution, prompting a resurfacing of old fears and terrors in the family's suburban community.

Maddy receives the news of Todd's escape and grows increasingly unstable, while Terry exhibits strange behavior that raises suspicions. As Todd searches for his mother to clear his name, a series of violent events unfold, leading to chaos and bloodshed within the neighborhood. The tension mounts as Todd's quest for truth clashes with Terry's dark tendencies, culminating in a confrontation that brings buried secrets to light and puts everyone in peril.