While making love in their tent during a work expedition in Nepal, photo-journalists Ted Harrison (Michael Paré) and his girlfriend Marjorie are attacked by a werewolf. The werewolf snatches Marjorie and Ted attempts to rescue her but gets bitten in his shoulder and thrown to the ground. Hurt but determined he crawls to his shotgun and manages to shoot the werewolf's head off but not before the beast kills Marjorie.
With the intent of living in isolation Ted moves back home into a trailer in the woods hours away from his lawyer sister Janet Harrison (Mariel Hemingway). One day in an effort to reach out to her and his young nephew Brett (Mason Gamble), Ted calls them up and invites them for a meal at his home by the lake. Upon seeing him again the family dog, Thor, begins to sense something wrong with "Uncle Ted" and goes into the woods tracking a smell, which leads him to human remains hanging on a tree branch. Meanwhile, Ted tells Janet that his girlfriend Marjorie broke up with him and returned to her home in Seattle, hiding the truth from her, and in an attempt at comforting her brother, Janet invites him to stay with them. Shaken and fearful of hurting them, Ted declines and Janet, Brett and Thor leave before the sun starts to set, at Ted's insistence.
The next day there is an investigation going on in the woods near Ted's trailer where the mangled bodies of several missing hikers and a Forest Ranger were found. Ted, under fear of being found guilty, calls Janet and tells her he's changed his mind. He parks his trailer in her yard in the hopes that in being near his family he'll be able to control himself. Thor, however, is aware of Ted's nature and becomes suspicious and eventually hostile towards him. Noticing that he goes out to "jog" at night with handcuffs, Thor becomes frenzied until Janet lets him out of the house. Tracking his scent, Thor follows Ted into the woods and finds him turned into a werewolf and tied to a tree while growling, clawing and trying to escape. Meanwhile, Janet starts looking for Thor and goes into the woods. Aware of her danger, Thor manages to find and distract her back to the house before she finds Ted.
The next day while making breakfast, Janet sees on TV the news coverage on the killings and confronts her brother about not telling her his true reasons for visiting her and invites him to stay permanently. While Brett is watching Werewolf of London (mistakenly confused for The Wolfman), he and Ted discuss werewolves and their existence, with Ted stating that it doesn't take a full moon to start the transformation and that he has "been acquainted with a few in his time" and Brett states that werewolves don't exist. While Brett throws out the trash, Ted tries to warn his sister and advises her to start listening to Thor and his sudden change in behavior and drops hints that the murders had been done by a wolf. She ignores his pleas and he retreats into his trailer where Thor follows him, waiting for him until the sun starts to set. Ted encounters a suspicious Thor but eventually leaves the trailer with the hopes of chaining himself again. With the sun setting Ted screams for Janet to take Thor away and when she does he rushes into the woods. Thor is afraid of Ted hurting his family and begins to bark until Brett lets him out of the house. He makes his way to the woods to find that Ted was too late and wasn't able to handcuff himself and has made his way into the backyard. Werewolf Ted attacks Thor but the dog fights back which wakes up Janet. Werewolf Ted is scared away when she turns on the bright deck lights. Janet sees Thor's injuries and, fearful of Ted's advice, calls the Sheriff and goes into Ted's trailer to notify him. She does not find Ted but instead finds his werewolf book, gruesome pictures of Marjorie's body and some of Ted's victims. She also finds a journal in which Ted details his pain and his turmoil with not finding a cure for his "disease" and his hopes of finding peace by his family's side. Werewolf Ted seems to lurk outside the trailer but Janet leaves safely, shaken but adamant about straightening things out with her brother. Later that night a "flopsy" who had previously tried to frame Thor for a false bite goes into Janet and Brett's yard with the intent of killing Thor but is instead attacked and killed by Werewolf Ted.
The next day the sheriff shows up and questions Janet about Thor and informs her of the "flopsy's" attack by a wild animal; his mutilated body's been found 100 yards away from her property. Remembering Thor's injuries Janet asks if the culprit could have been a wolf but the sheriff says no and advises her to give up Thor to the dog pound. Not believing Thor could be the killer, she confronts Ted, who provokes Thor to attack him. As a result, Thor is taken to the dog pound. Seemingly more confident and accepting of his bloodlust, Ted "marks his territory" by urinating in Thor's doghouse (as Thor had done to his trailer earlier) and shows hostility towards Brett, who feels Ted is the reason Thor was turned in. Brett pretends to go to sleep but packs his backpack and sneaks out of the house to free Thor while Janet confronts Ted in the woods with a hand gun and 8 rounds. In the woods, Ted accuses his sister of not listening to his warnings and knowing the truth all along. As he begins to transform, Janet flees in panic back to the house with Werewolf Ted on her trail. Meanwhile, Brett reaches the dog pound on his bicycle, breaks in and frees Thor, who takes off running and gets to the house just as Werewolf Ted is about to attack Janet. A vicious fight ensues between them with Thor savagely biting and injuring Werewolf Ted several times and Werewolf Ted throwing Thor across the room and seemingly killing him. Brett, having followed Thor and worried about his mom, goes into his room and is strangled and held up by his throat by Werewolf Ted. Seeing an opportunity, Janet unloads all eight rounds into Ted, who releases Brett and spins from the shots. Hurt but still alive he growls at the now defenseless Janet. However Thor gets up, gets between them and throws himself on Werewolf Ted, knocking them both out the window and into the yard. Werewolf Ted is severely injured but gets up and retreats into the woods. Though Thor is injured as well he follows Werewolf Ted and tracks him down until sunrise, where a now human Ted emerges from behind a tree bruised, beaten and bloody. Standing his ground and ready to attack, Thor whimpers in reluctance but Ted tells him to "do it" and with no more hesitation Thor lunges at him and finishes him off.
Some time later Janet's house is being repaired and she and Brett are seen petting Thor, who is bandaged and recovering from the fight. Janet apologizes for blaming him and putting him in the dog pound. Suddenly Thor (as a werewolf) savagely growls at her. Janet wakes up alarmed and quickly realizes it was just a nightmare as she, Brett and Thor are fine and at peace.Michael Paré — Uncle Ted
Mason Gamble — Brett
Mariel Hemingway — Janet
Ken Pogue — Sheriff Jenson
Hrothgar Mathews — Flopsy
Johanna Lebovitz — Marjorie
Gavin Buhr — Forest Ranger
Julia Montgomery Brown — Reporter
Primo — Thor
Reviews were extremely unfavorable. Rotten Tomatoes gives it a score of 38% based on 8 reviews.
The MPAA rated this film an R for "horror violence and gore, brief language, and a scene of sexuality". Originally, the film was issued an NC-17 rating, so a few seconds of graphic sex and violence were cut from the pre-title sequence.
The movie made many significant changes from the novel, particularly in the make-up of the family, which in the novel consisted of two parents and three children, as well as the dog, who sees the family as his pack, which must be defended at all costs. The dog's perceptions of events are treated in great detail, as is the relationship between him and his human family, and his confusion as to whether the werewolf is a threat to his family that must be eliminated, or a pack member who must be respected. These subtleties mainly did not make it into the film.
The film was released on DVD in a snap case on October 3, 2000. It was released for the first time on Blu-ray on July 19, 2016. The Blu-ray edition from Scream Factory (a Division of Shout Factory) featured both the theatrical and director's cut of the film. The director's cut is only about a minute or so longer with additional gore cut in order to receive an R rating. The Blu-ray included a commentary track by writer-director Eric Red, new interviews with the actors, Red, stunt coordinator Ken Kirzinger, and special make up effects artist Steve Johnson (special effects artist). The special features also included a selection of storyboards and the theatrical trailer for the film.