Brock Blodgett and his wife Shannon drive along a country road and come to a stop at an intersection. They've been arguing and Brock is an ass. At the intersection, six cars are already stopped.
Something large hits their car and the engine stalls. They fight over whether it was a person or an animal, Brock belittles her for thinking it's an animal.
It's clear now that all the cars are stalled, they don't even have lights on. Brock tries to restart the car, but it's dead. Fog rolls in and surrounds the cars, Brock and Shannon can't see much beyond their own car.
A police officer steps out of one of the cars, but he's not sure what's going on. Shannon hears a growl in the fog. The officer tries to turn on his maglite, but it doesn't work.
In the future, Shannon sits in a police interrogation room. Two detectives, Mitchell and Alvarez are questioning her. She tells them that blood splashed across their windshield as the monster killed the cop. The detectives are baffled and ask her more questions, but she doesn't know much.
In the present, Shannon screams and Brock tries to shut her up and he's not nice about it. He thinks the killer is a man with a gun, but she argues there was no gunshot. Just then, the monster bumps their car.
Brock tells her to roll up her window, but the car has no power and the car is dead. He tells her to open the glove compartment. She does and a gun is inside. She gets angry because they've talked about it and she hates guns and doesn't want them around their kids.
She hands him the gun and he acts ready for the monster. It hits the car again, still unseen in the fog.
In the future, the detectives question her, but she didn't see anything. She says it jumped on the hood of the car and it left claw marks. She was too scared to look at it.
In the present, Brock and Shannon cringe from the windshield. Brock points the gun at it, but doesn't fire. She tells him to do something, but he refuses to damage the car. The monster leaps onto the roof of the car.
In the future, Shannon tells the detectives that she heard a sniffing sound coming from outside the car.
In the present, Brock and Shannon crouch down, away from the roof. The monster leaps from the car, leaving heavy damage to the roof. Brock can't handle it, he checks the gun and hops out of the car. She doesn't stop him and shuts the door behind him once he's gone.
In the future, Shannon tells the detectives she lost all sense of time, but that she definitely heard a growl. Then three gunshots. And that was it. Nothing else happened until the fog lifted.
In the present, the fog lifts and all the cars' lights come back on. She's the only one in any of the cars. She turns the key and her car starts up.
In the future, the detectives finish questioning Shannon, who noticeably isn't wearing her wedding ring.
In the present, Shannon drives the Lexus away from the intersection. She drives into town and stops in front of the police station. She considers it and DOESN'T go inside.
She drives to the house she and Brock share. She turns the car off and takes the keys out. She looks at the house. She starts the car up again and drives away.