The film revolves around journalist Richard Hall (Richard Armitage) and his children Aidan (Jaeden Martell) and Mia (Lia McHugh). Following a family tragedy that deeply traumatizes the two kids, the tension between them and Richard is amplified upon Richard's insistence that the kids bond with his new girlfriend Grace (Riley Keough), who he plans to marry.
Christmas proves an opportune time for Richard to enact his plan: having the kids and Grace stay at the family's remote lodge for the holidays. Though Aidan and Mia eventually accept, they hold firm opposition to Richard's marriage plans and suspicions towards Grace — sentiments not helped by Richard promptly departing due to work obligations, leaving them essentially isolated from civilization.
Just as the three begin to live in relative peace, a snowstorm hits and traps them in the lodge, at which point strange and increasingly frightening events occur, seemingly summoning long-buried relics of Grace's dark past...
This film provides examples of:
- Abusive Offspring: They adored their mother before her death, but Aiden and Mia psychologically torture and gaslight their stepmother-to-be, Grace, which includes severe mental abuse and Aiden peeping on her in the shower, which accidentally leads to her killing their father Richard.
- Arc Words: "Repent."
- Ate His Gun: Laura commits suicide by shooting herself through the mouth, which is fully depicted on camera.
- Backstory Horror: Grace had a traumatic and disturbing childhood, which makes Aidan and Mia especially suspicious of her.
- Big Brother Instinct: Though he gets on her nerves like any big brother, Aidan clearly loves and is very protective of Mia.
- Blatant Lies: Richard insists to a visiting Laura that Grace isn't home despite having two wine glasses out. Laura even looks out the window to see Grace quietly leaving.
- Break the Cutie: Poor Grace. Every new event just seems determined to crush her spirits.
- Canine Companion: Grady, Grace's beloved dog. He's extremely important to Grace, who found something to live for in him after the events of the cult. Small wonder that her discovering his body is what finally breaks her sanity.
- Censored Child Death: Possibly overlapping with Improbable Infant Survival, it ends with the strong implication that Grace is about to kill Aidan and Mia. However, the fact that we don't see it occur has led to some speculation that Grace actually came back from her psychotic break and was "only" trying to terrify Aidan and Mia, which might be worse because it leaves the question of what she actually will do to them afterwards.
- Chekhov's Gun: The heirloom gun that Richard teaches Grace how to shoot, which becomes her weapon of choice during her mental breakdown.
- Creepy Child: There's something inherently off about Aidan and Mia. The trauma they put Grace through places them firmly into this camp.
- Creepy Dollhouse: One of the biggest reasons behind incessant comparisons between this film and another dysfunctional family horror. The film begins with the eerie surroundings of a dark house filled with religious belongings, before revealing it to be the contents of Mia's dollhouse. The image is revisited throughout the film.
- Cult: Grace is the daughter of the leader of a fundamentalist cult; her father had convinced them all to kill themselves in order to join Jesus Christ, but had left her alive to carry on his message.
- Danger — Thin Ice: Grace falls through the ice while trying to rescue Mia's doll, but she's rescued before any serious injury, though. A Nightmare Sequence later on has her reenact this; however, her father emerges from the waters to pull her down.
- Dark and Troubled Past: Poor Grace. She grew up in a cult headed up by her father, and was the sole survivor of a mass suicide. She's clearly still reeling from the whole thing, and has a lot of trauma surrounding religion.
- Dead All Along: Subverted. Aidan and Mia intentionally convince Grace that this is what happened... so she makes it a reality. (Probably.)
- Deconstructor Fleet: The story deconstructs multiple different subgenres and tropes associated with it, particularly the horror tropes surrounding the story where an unwanted stepmother moves with her stepkid(s) to a foreign location, such as Beetlejuice and House at the End of the Street.
- The Creepy Child horror trope. Mia and Aiden both behave creepily, but that isn't because of anything sinister, but because they're explicitly trying to drive Grace insane, and because they're grieving their mother.
- The Enfant Terrible. Neither Mia or Aiden are fully good or evil; Aiden is the coldest and morally darkest, but he's mourning his mother and is deeply protective of Mia, even when it puts him in mortal danger.
- The Wicked Stepmother. Grace tries to be a Good Stepmother, but she isn't this either, because she has been pushed into a situation she doesn't understand and isn't equipped to handle, then has a psychotic break and kills them all.
- The Dead All Along twist. Mia and Aiden deliberately make it look like this has happened to get rid of Grace. Then, in the end, it - possibly - comes true.
- Determinator: Wearing nothing more than a couple of blankets, Grace walks for miles in a snowstorm to try to get help. This goes up to eleven with the reveal that nobody is dead or in purgatory (and incapable of dying) — she really did walk that far on her own.
- Downer Beginning: The film opens with Laura dying by suicide and her funeral, which traumatizes Mia and devastates Aidan.
- Downer Ending: The children gaslight Grace to the point where she loses her mind and fully believes they're all in purgatory. Richard is killed while trying to calm Grace down, and after the children fail to escape, Grace prepares to kill them both and then herself, putting tape on their mouths like the dead members of her old cult.
- Driven to Madness: Aidan and Mia have been attempting to do this to Grace, likely in order to break her and Richard up.
- Driven to Suicide:
- The fundamentalist cult, led by Grace's father, did this prior to the events of the film.
- Laura kills herself after learning that Richard plans on finalizing their divorce and marrying Grace.
- Enfante Terrible: Mia participates in the Gaslighting scheme, though Aidan appears to be the ringleader.
- Fan Disservice: While Riley Keough's nude body post-shower is a welcome sight, the pre-existing creepy atmosphere and the fact that Aidan's been watching her sours the mood quickly.
- Gaslighting: Aidan and Mia drug Grace, kill the phones, and hide all of their belongings, leaving her breadcrumbs before outright insisting that they all died in an accident and that they need to repent.
- Gone Horribly Right: Aidan and Mia wanted to drive Grace insane. They succeed in the worst possible way with both Richard's demise and their own assured as a result.
- Hates Their Parent: Aidan and Mia don't hate him, but they are angry and upset at their father for leaving their mother and driving her to suicide. When it comes to their stepmother-to-be Grace, however, this trope is played completely straight.
- Heel Realization: Mia, at least, seems genuinely remorseful over her actions once things go too far.
- Hope Spot: After Grace shoots Richard, the children manage to escape to Richard's car and try to drive away... only to almost immediately get stuck in a snowbank.
- Horror Doesn't Settle for Simple Tuesday: They're at the lodge for Christmas (and New Year), though after all of Grace's attempts to decorate the house disappear and leave them in darkness, things get significantly grimmer.
- Innocently Insensitive: Grace wears a hat she found in the lodge, not realizing it belonged to Laura until an upset Mia informs her.
- Instant Waking Skills: Grace tends to wake quickly after her nightmares.
- Ironic Name: Grace, as in "the grace of God," is a cult survivor who now dislikes religion.
- Kids Shouldn't Watch Horror Films: Grace plays The Thing (1982) for the children, but quickly realizes that a violent, disturbing film about a Dwindling Party trapped in a snowy hellhole probably isn't the best for them.
- Knight Templar Big Brother: Aidan is extremely protective of Mia and pushes her behind him when Grace is on her finale rampage.
- Loving a Shadow: It's natural that Aiden and Mia would miss their biological mother after her death (not that the plan they put into motion as revenge for her isn't absurd) but they didn't seem to realize Laura might not have cared enough about them in turn. In the opening, Laura was unhealthily focused on getting back together with her ex-husband, who was already moving on, and shot herself out of her own misery, despite the fact she had two children who loved her and whom she should have kept going for.
- Minimalist Cast: The brunt of the plot centers on three main characters. There are only five (six, if you count Grace's dead father) speaking characters overall.
- Misplaced Retribution: Richard was wrong to try and force the kids to spend time alone with Grace when they clearly were not ready and were still processing their mother's death, but the kids blame Grace for everything, even though she didn't actually do anything wrong.
- My Car Hates Me: Richard's car gets stuck in the snow right when the children are trying to escape.
- My God, What Have I Done?: The death of Grady, Grace's beloved dog, is enough to bring Aidan and Mia to attempt to reverse course on their plan, with Mia in particular showing genuine remorse over what she's done and concern for Grace.
- Nice Girl: Grace makes a genuine effort to connect with Aidan and Mia and make their Christmas special, but they rebuff her at every turn, suspicious of her due to her past.
- Nothing Is Scarier: Though nothing is wrong with the lodge itself, it definitely feels haunted. When the trio's belongings vanish, it only seems more sinister.
- Oh, Crap!: Aidan and Mia when they realize that they've gone too far with Grace, and are also unable to restart the generator or give her back her medication.
- Parents as People: Richard clearly loves his children, but also pushes them to spend Christmas with Grace when it's clear they're not ready to accept her into the family.
- Parent with New Paramour: The central problems in the film are brought about as a result of Richard dating Grace and the kids not accepting her.
- Pet the Dog: Aidan clearly loves Mia very dearly. In one of the first scenes, the night of their mother's funeral, he brings a blanket and pillow into Mia's room and sleeps on the floor next to her bed, holding her hand to comfort her.
- Polar Madness: Set in a cabin over a snowbound, freezing Christmas, the heating stops working, and Grace starts to hear the voice of her dead father, leading her to believe that she may have accidentally killed everyone in the cabin by using the space heater on the first night. Made even more explicit by the fact that she hasn't; this is in fact all caused by gaslighting from Aiden and Mia. However, when Grace tries to escape the house to get help and look for her beloved dog Grady, she gets so disorientated, lost, and nearly dies in the snow that an unoccupied house convinces her that Aiden is right and they are all dead.
- Pretty Little Headshots: Played straight with Laura and averted with Richard.
- Religious Horror: Christian themes and iconography abound, which Grace struggles with, being a survivor of a fundamentalist suicide cult. This is actually being invoked by Aiden and Mia, as they're aware of Grace's past in the cult, and are trying to drive her insane with it. It works. Too well.
- The Reveal: The trio still has all their belongings; Aidan and Mia had drugged Grace and put them in a hidden crawlspace. Mia really has been calling Richard the whole time to prevent him from getting suspicious. The children had been planning on gaslighting Grace before the trip and were responsible for all the details of her hallucinations.
- Sanity Slippage: Grace's sanity slowly breaks during the trip as a result of stress, hunger, cold, medication withdrawal, and anxiety. Then it gets even worse when Aidan and Mia convince her that they're all dead and in purgatory, and start making her believe that she's hearing her father's voice telling her to repent. Then she discovers her dead dog. By the time the children realize they've gone too far, it's too late to bring her back, and she fully succumbs to the belief that they're in purgatory and kills them all.
- Security Blanket: Mia has her doll, and Grace has her dog Grady.
- Shout-Out: Grace's dog being called Grady in reference to the first caretaker from The Shining.
- Spooky Painting: There's a religious painting on the wall, which Grace hates, and even changes spots while eating to avoid looking at it.
- Teens Are Monsters: Aidan is manipulative and appears the to be mastermind behind the scheme to drive Grace insane.
- Too Dumb to Live:
- Mia and Aidan decide driving the cult survivor insane in an isolated area with no route of escape is just a wonderful little strategy. Guess how this turns out.
- More specifically, even though she is young, Mia going down the stairs instead of just going to the bathroom in the corner of the attic while her stepmother is in the middle of a psychotic break that she caused and Aiden not stopping her.
- Richard leaving his children, who are in mourning for their mother who violently committed suicide and repeatedly tell him that they really don't want to go, alone in the wilderness with their unstable stepmother, who survived a mass suicide.
- Mia and Aidan decide driving the cult survivor insane in an isolated area with no route of escape is just a wonderful little strategy. Guess how this turns out.
- Troubling Unchildlike Behavior: Mia is obsessed with her mother's death and clearly views the doll of her as the real Laura, to an extent. Then there's Aidan peeping on Grace in the shower. To say nothing of their dedicated gaslighting. Richard is only clued into a possible issue when he looks into Mia's dollhouse and becomes suspicious of what they've been planning.
- Twisted Christmas: The film takes place from a couple of days before Christmas to just before New Year, as Grace, Mia, and Aiden all hunker down in their remote snowy cabin.
- Wham Line: Near the end of the film, which reveals the truth behind the strange events from inside the lodge.Aidan: We were just pretending.
