Ellen receives mask by mistake, has hallucinations, husband leaves when car breaks down, escapes home during hallucination, husband tells her not to call police as she imagines things.
Ellen orders an African hand-carved mask from Rome to resolve her fertility problem with her husband William. After receiving a wrong mask, Ellen insists that the demon Nightmare Man is attacking her and she needs pills to keep him under control inside her, but the doctors diagnose her as a paranoid-schizophrenic. On the way to be committed to the remote Devonshire Institute, the car runs out of gas and Bill leaves Ellen in the car while he walks to a gas station 10 miles away. Ellen is attacked by the Nightmare Man but she escapes through the woods, reaching the house of Mia, who shelters her and calls Bill, who reveals that she is delusional so they decide not to call the police.—Claudio Carvalho, Rio de Janeiro, Brazil
After receiving a mysterious demonic African mask in the mail, ELLEN MORRIS is attacked by a "being" she refers to as THE NIGHTMARE MAN. Her doctors and husband, William believe Ellen is a paranoid schizophrenic and needs to spend some quality time at a mental facility for further examination.
On the way to the hospital, their car runs out of gas. William walks to the nearest gas station as Ellen waits in the car watching the sunset. Alone once again, Ellen is attacked by the mysterious Nightmare Man. She manages to flee into the nearby woods... but is this man/demon real or is it all in Ellen's mind?
Running for her life, Ellen stumbles upon a country house where two young couples are vacationing for the weekend. She barely escapes the Nightmare Man by running into their house, claiming there's a killer outside! The couples are suspicious and wary, and contact William on his cell phone. He warns them of Ellen's condition and tells them to be careful. "She may be dangerous to herself and others." William promises to arrive there as soon as he can.
One by one everyone, except Mia and Ellen are killed by the mysterious and ever elusive killer.
Then William arrives and it is disclosed that he is the one who had hired a killer to dress up as the Nightmare Man to get his wife killed.
When this killer finally tries to kill Mia as well, Ellen turns into a demon. It is revealed that an actual demon was inside her all the time.
In the climax Mia kills Ellen and the demon transfers itself to and takes over Mia's body.
In the final scene Mia turns into the demon herself.
