In rural Pennsylvania, one of life's great losers looks up from behind his gas station counter and notices that a big old Buick is still sitting out front with its driver nowhere in sight. After a quick search, he can't find the driver but fears he may have fallen into the river, so he calls the state police. When the police arrive, they cannot find any trace of the man and take the car away as potential evidence. Only... only it's not really a car. There's no way it can drive, it's missing essential parts and looks like it never had them and seems more like it teleported in judging by the lack of mud.
And that's just the start because ''things'' come out of it - the story--as written by StephenKing--is framed as the current Sergeant Commanding and some other officers explaining the thing to the traumatized son of an officer who was tragically killed by [[ContrivedCoincidence that same loser]] years later.
* AlienGeometries: It seems to have a direct connection to another universe, perhaps another world linked to Franchise/TheDarkTower.
* AlienSky: In the climax, Sandy pulls Ned out of the car, and in the process, gets a brief glimpse of the world on the other side, an alien world, along with remnants of the people absorbed by the Buick.
* AmbiguousSituation: Basically the point. You don't get many answers by the end. There are multiple theories, but you don't know if any are true.
* ArcWords: Curiosity killed the cat, but satisfaction brought him back.
* AssholeVictim: [[spoiler:The Neo-Nazi Brian Lippy, who was arrested for reckless driving and beating his girlfriend, is "eaten" by the Buick after it's implied he tried to hide in the trunk.]]
* AttackOfTheKillerWhatever: Well, it ''looks'' like a car, anyway.
* BittersweetEnding: [[spoiler:The Buick remains a complete mystery by the end of the novel... but newly hired deputy Ned notices that the once-pristine car is showing signs of damage, meaning it's dying and whatever threat it represents will soon fade.]]
* BizarreAlienBiology: The creatures that come out of the Buick. In addition to the visually apparent weirdness, there is something about their chemical makeup that makes them start decaying almost instantly. An [[AlienAutopsy autopsy]] that was attempted on one creature does not go well. [[spoiler: Sandy later realizes that if some of the blood-like black substance that squirted out of the bat-creature had gotten into Curtis' mouth, he would have died.]]
* CallASmeerpARabbit: Various things come out of the trunk of the Buick. They tend to get called things like birds and bats when it is very clear that that is not what they are at all.
* ContrivedCoincidence: Subverted. Curtis is eventually killed in a hit and run by the same guy who called the police about the Buick, but Sandy speculates that the Buick somehow arranged it.
* CoolCar: It'd be an impressive vehicle if it actually, you know, was a vehicle.
* DepartureMeansDeath: Things from the trunk can't survive in our world, and it's assumed stuff from ours wouldn't survive there either. No one knows why, although it's theorized it's due to the change in the air.
* DrivenToSuicide: [[spoiler:Eddie at the end, though it was set up to seem as though it was Ned.]]
* EldritchAbomination: One officer notes that looking at the things that come out of the trunk made him feel like ''[[MindRape his EYES were being raped]]''.
* HumanoidAbomination: The mysterious driver of the Buick that originally left it at the gas station at the start of the story, and who disappeared behind the building. The gas station attendant described him as looking "melted", and he had a very odd posture. Outside the novel, said driver is generally theorized to be a [[Franchise/TheDarkTower Low Man]].
* HumansAreCthulhu: [[spoiler:The one thing that makes it out of the Buick's trunk alive sees the officers as just as mind-breakingly horrible as they see it.]]
* HumansThroughAlienEyes: [[spoiler:The above creature was not afraid as it was torn to bits, only very, very confused at what these horrible things were doing to it.]]
* [[spoiler: MercyKill: The first time something comes out of the Buick that lives long enough for the officers to interact with it, the station dog, Mister Dillon, goes nuts and attacks it, apparently ingesting some of its flesh. The poor dog starts burning from the inside out, and one of the officers decides to shoot him, as there is nothing else they can do to help him.]]
* MrsRobinson: Invoked. Sandy wonders if Shirley might be telling Ned so much and so easily because he's good looking and wonders if she might be thinking of 'playing Mrs Robinson' but nothing ever comes of it.
* [[MyGodWhatHaveIDone My God, What Have We Done?]]: [[spoiler: After they kill the previously mentioned "live birth" creature, Shirley says "We killed a ''thinking being.'' That's murder."]]
* NoBiochemicalBarriers: Averted, as the creatures that come out of the Buick pretty much die and sometimes rapidly decompose when exposed to the open air. It's theorized it would be the same for someone going into their world.
* OhCrap: The general mood whenever someone at the station realizes the Buick is ''doing something'' out in that shed...
* PoliceBrutality: Commented on in-story. One of the cops notes that small town cops are good enough, but they get a bad rap from bigger cities: for every honest, hard-working cop, there's a power-tripping asshole waiting to beat you.
* PosthumousCharacter: Ned's father Curtis, whose death brought Ned to Troop D and whose obsession with the Buick provides a lot of the story. Other deceased officers make appearances in the flashbacks as well.
* RuleOfScary: This is one of the themes of the book. The creatures that come out of the Buick, and the Buick itself, make no sense by human standards and will probably never really be understood. The same goes for the motivations of the driver who abandoned the Buick, there is no elaboration of who, or more likely, what he was, just that he drove the "car" to the gas station, left it there, and then disappeared.
* SurrealHorror: Big time.
* TheseAreThingsManWasNotMeantToKnow: The attitude of most of Troop D towards the Buick. Even the ones who do want to know more about it, Curtis and the previous sergeant, Tony Schoondist, don't want to call in any scientists to look at it beyond their usual forensics guy, mainly because they feel it's "theirs" now and don't want to give it away.
* VomitingCop: The horrible things that come from the Buick make several cops throw up.
* YouCannotGraspTheTrueForm: The Buick itself. The things are incredibly alien and horrible, but you can see them properly. The Buick is speculated to be something along the line of the breathing valve for an EldritchAbomination's scuba gear.
** It's also speculated that, for all the scary power the Buick possesses the vehicle was left behind because it was somehow ''broken''...