"LET ME IN! NOOOOOWWWW!"
- At first it sounds like a boring film about how Michelle would turn around and reconcile with her ex after her first fight with him, right? After the jump scares in the opening sequence, you wish it was just that.
- Howard, and everything about him. He seems well-meaning at first, but is shown to be completely off the rails as the film goes on.
- John Goodman manages to be creepier, more menacing and more terrifying than any CGI monster of modern cinema.
- The hysterical survivor woman outside the door of the shelter who is suffering from the effects of the alien bioweapon that has heavily disfigured her, who ends up banging her head against the door til there's a good-sized amount of blood as she enters a state of insane rage.
- She even starts out coherent and normal before her speech dissolves into screaming "YOOUUUU" and "HUMAAAN!".
- The sight of Emmett's corpse dissolving in acid. It's quick but still unpleasant and kinda sad to watch.
- Howard's scarred face after falling into the acid.
- The reveal that, for all of his complete lunacy, Howard wasn't entirely wrong about the surface not being safe. There's an alien invasion going on across the planet.
- The tracker hound who gets released by the alien patrol craft has no eyes, just a giant Lamprey Mouth.
- When the three bunker survivors are playing a guessing game together, Emmett has a pretty simple card: Little Women. Howard gets the first part right, but even when prompted with "Michelle is a...", guesses just about everything but "Women" — as if the word "woman" itself in reference to a female adult and not words related to little girls and little princesses, is physically painful for him to acknowledge. It doesn't sound like much, but his hemming and hawing and the noises he makes are incredibly creepy. Then when it's his turn... it gets much worse.
- After all, Howard sees Michelle as a substitute for his daughter Megan, and he can't bear the thought of his daughter growing up, so he can't even process the idea of Michelle being a "woman".
- During the card game, Howard's attempt to describe Santa Claus is terrifying, even outside of Emmett and Michelle thinking he's cottoned onto their plans. It starts with "I am always watching you..." and just gets creepier from there. Imagine being his family at Christmas time. No wonder his wife and daughter turned against him.
- Why would Howard need a room with a secure door to keep someone? Because he had plans to abduct another girl - implying he would've eventually killed Michelle anyways.
- What Michelle finds in the air filtration room: a window with the word "Help" scratched on it from the inside, and a single bloodstained earring. Maximum creepiness with minimum effort.
- Just picture this entire situation from Michelle's point of view. You wake up, chained to a bed in a bunker. You have no idea where you are or why you're here, until a man tells you that there's been some kind of massive attack and everyone above ground is dead. And from the small glimpses you're allowed of the outside world, it does seem that, indeed, something horrible has happened and you have no idea what. Then the guy who's hosting you in his bunker starts to become more and more unhinged, and you discover that his motives may not be as altruistic as they appear to be. As one review pointed out, this movie makes the idea that there isn't anything wrong with the outside world even scarier than the idea that there is.
- And then after you escape the bunker, you find out that despite the fact your host was clearly paranoid and psychotic, he was right. Aliens have invaded the planet. And now they're coming for YOU.
- Howard is emphatic that he's "not some pervert", but that's about all he has going for him — imagine being in Michelle's position and realizing not only has this man abducted someone before, but his previous abductee was a young girl kidnapped as a probable replacement for his teenage daughter. Whose clothes you are now wearing and whose belongings Howard suggests you start familiarizing yourself with. Only you're not exactly his type... you're not a teenager, you're thirty, and you've already gotten on his bad side by not acting like the perfect obedient daughter. Sounds like the clock is ticking.
- If that wasn't bad enough, that Howard cleans himself up after killing Emmett (via giving himself a shave and putting on nicer clothes) and is obviously glad to have Michelle all to himself could be seen as implying that his warped affections for her aren't even strictly "platonic"...
- Howard suddenly becoming soft-spoken and conciliatory toward Michelle after shooting Emmett in the head in front of her. His sudden angry outbursts are already scary enough (the ARG material suggests they started before Megan left, and were a factor in Megan and her mother fleeing Howard in the first place) but his sudden changes from anger to seeming gentleness are really something else.
- Emmett, upon viewing the Polaroid image Howard had shown Michelle, gives a sudden and harrowing reveal that the girl in the image isn't actually Howard's daughter. Becomes more frightening when they realise it's a local girl whom he abducted, held prisoner as a surrogate daughter, and then murdered when he got bored.
- When Michelle escapes the bunker, she locks Howard in there as the place sets on fire. Shortly after, she hears a small bang within the bunker, before it explodes in a ball of fire that erupts from the secondary surface hatch. The nightmare fuel kicks in when you realise that it exploded not long after she escaped, and Michelle was mere minutes away from being blown to pieces along with Howard. Had she not made it out, she would have been killed in an incredibly gruesome manner.
- The final shot of the movie: the lightning in the sky reveals a silhouette of an alien space craft that is much larger than the one Michelle fought.
