As the Barrett family's peaceful suburban life is rocked by an escalating series of disturbing events, they come to learn that a terrifying and deadly force is after them, one which may have arrived from beyond the stars.

The Barrett family-mother Lacy, father Daniel, older son Jesse, and younger son Sammy-reside on a quiet suburban street in an unnamed American city. Daniel is currently unemployed, placing the burden of supporting the family on Lacy, who works as a real estate agent. Their two sons enjoy a happy relationship and communicate with each other from their beds via walk-talkie. A number of strange occurrences befall the family. During the night, the contents of the kitchen are rearranged in bizarre configurations. The house alarm is set off when it detects that all entry points were breached simultaneously. Sammy suffers a fit while playing soccer and Lacy is shocked when hundreds of birds suddenly crash into the house. One night, Lacy is awakened by a sound from Sammy's room. When she goes to check on him, through the darkness she sees a figure standing over his bed. She turns on the light to find an empty room. Sammy is found walking away from the house but cannot remember leaving. Lacy, Daniel and Jesse each suffer catatonic episodes and regain consciousness with no memory of their experiences.