Mary Portman (Watts) is a widowed child psychologist living alone with her paralyzed stepson Stephen (Charlie Heaton) in rural New England. She has to deal with the trauma of the car accident that killed her husband and paralyzed Stephen with the help of her psychologist friend Dr. Wilson (Oliver Platt).
When a deaf young boy named Tom (Jacob Tremblay) stays with them for a while before mysteriously vanishing, Mary has to survive an approaching winter storm while trying to find him. On top of that, strange events occur which seem to indicate that there is someone (or something) else in the house that wishes them harm, and Mary must fight to stay sane
No relation to Intruders which was also released as Shut In.
Shut In provides examples of:
- Adult Fear: What if your stepchild turned out to be insane?
- All Just a Dream: At one point, Mary appears to drown Stephen for some unexplained reason. However, it then cuts to her waking up, revealing it to be a dream.
- Cat Scare: More like "Raccoon Scare". At one point, a raccoon jumps out and scares Mary, complete with Scare Chord.
- Cute Mute: Tom is a deaf little boy who is silent for the entire film.
- Disappeared Dad: Stephen's father, who dies at the beginning of the film.
- Downer Beginning: The film's prologue ends with a car accident that kills Stephen's father and supposedly paralyzes Stephen.
- Gory Discretion Shot: The film cuts away right before the car that Stephen and his dad are in impacts with the truck in the prologue.
- Green-Eyed Monster: Stephen has secretly been in love with his stepmother, and he gets jealous when she shows concern for Tom.
- Idiot Ball:
- A pretty spectacular case. Somehow, neither Mary nor any of Stephen's doctors have noticed that he has been faking his paralysis over the course of several months.
- A smaller one: Mary tries to calm down Stephen (who is clearly insane) by telling him that he's a good boy, despite being a psychologist. Unsurprisingly, it doesn't work.
- Jump Scare: The film has a lot of these. A particularly egregious one is the Cat Scare mentioned above.
- Product Placement: Dr. Wilson is shown to be using an iMac and a MacBook in his Skype sessions with Mary, with the Apple logo prominently displayed in several shots.
- The Reveal: In the film's third act, it's revealed that Stephen has been faking his paralysis the whole time, and he's the one who trapped Tom in the house and has been drugging Mary throughout the film.
- Sanity Slippage: Mary has to deal with this throughout the film, as she soon starts seeing strange things in her house.
- Slipping a Mickey: Stephen has been drugging his mother the whole time, which was the cause of her strange visions.
- Snowed-In: The film's premise revolves around Mary and Stephen being trapped in the house by the winter storm and having to survive it.
- Teens Are Monsters: Stephen. He will do anything to have his stepmother all to himself, including trapping Tom (a child) in the house.
- Time Skip: The bulk of the film occurs six months after the prologue.
- Trailers Always Lie: The trailers set this up to look like a paranormal horror movie.
- Widow Woman: Mary.
- Yandere: Stephen for Mary, very much so.