Joe Spelliner, a neon sign artist, is leaving a party and drives away in his car. A dog crosses his path and Joe goes off the road trying to avoid it. As he climbs out of the car, a crowd of people appear almost instantly and lookdown at him. They start to move him and Joe realizes that they're stealing his breath. The ambulance arrives and the crowd disperses.
Later, Joe wakes up in the hospital and tells the doctor that the crowd seemed to come out of nowhere. The doctor assumes that he's shook up from the accident and that it isn't possible for time to have passed as quickly as he thinks.
Once Joe is released, he goes back to work in his studio and his friend Morgan, a reporter, shows up. As they drink, they hear a car crash outside and go to the window. Joe times the event and watches as a crowd gathers within 20 seconds. They go down to the crowd and Joe looks over the crowd. He sees several people that were in the crowd at his accident. Joe grabs one of them and demands answers, but the crowd member starts to get angry and Morgan pulls his friend away. The ambulance arrives and the crowd dissipates again, and Joe asks a nearby news photographer for his film. As they go back to Joe's studio, Joe asks Morgan to get photos of the crowds at other accidents, and insists that it's the same people and they try to kill accident victims.
Joe begins prowling the streets, looking for car accidents and filming the crowds that gather. He and Morgan go over the footage and Joe discovers that the same people are in the crowd at different accidents, no matter what location or time of the day. Some of them are distinct, but one of them lurks in the shadows and Joe can't make out who it is. When Morgan wonders who they are, Joe shows him photos of past accident victims: each one is a member of the crowd. Joe believes that each victim dies and then comes back to haunt other accident scenes and kill the injured to bolster their ranks. Joe wants to meet the crowd members and get answers from them. Morgan worries what will happen when the crowd realizes someone knows who they are, but Joe insists that it doesn't matter.
Joe and Morgan go looking for accidents. Finally, Joe senses an accident nearby and has Morgan stop the car. They see an old man from the crowd walk by, and the old man turns and asks what they're doing there. He turns and goes and Joe follows him while Morgan circles around. Joe finds another crowd member waiting for him and retreats in horror. The man follows him and Joe runs back to the car, only to find the old man waiting for him. Joe brushes past him and gets in the car, and then tries to escape. The crowd members are in the streets and Joe tries to swerve around them. He almost gets clear but hits the last figure in his way: Morgan.
The car flips over and the injured Joe manages to pull himself out. He runs to the crowd and shoves through them, but realizes that Morgan is dead. As Joe looks up, he sees Morgan standing in the crowd. Morgan blankly stares at his own body, and then disappears with the rest of the crowd.