A young man named Kurt Kunkle is obsessed with being a social media star and becoming viral. A child he used to babysit, Bobby, is now an internet star who frequently makes live streams and has high viewer numbers making Kurt jealous. Kurt works as a driver for a rideshare app called Spree, then fits out his car with cameras, and begins a new Livestream one day titled “The Lesson” where he instructs viewers on how to get famous on social media.

Kurt starts picking up passengers and killing them with poisoned bottles of water that he hands out in his car. Kurt spends his time killing and disposing of his passengers but doesn’t have any viewers besides Bobby who believes the killings are fake and accuses him of being boring. While driving a new passenger and trying to get him to drink the water, Kurt accepts another passenger, Jessie Adams who is a comedian with a large social media following. Kurt is awestruck by Jessie who is unimpressed by Kurt and his obsession with gaining social media followers and leaves the ride. Kurt then kills the other passenger.

Night falls and Kurt picks up and manages to kill three passengers all at once, but this fails to go viral. Kurt learns that Jessie will be performing in a comedy show that will be live-streamed to millions. Kurt goes to Bobby’s house, demanding that Bobby shares Kurt’s stream but Bobby refuses and starts live-streaming their argument, attracting a large viewing audience. Kurt kills Bobby and takes his gun before live streaming for Bobby’s fans who assumes the murder is fake and spends their time insulting Kurt. Kurt’s father Kris asks him for a ride to a club where he is performing, claiming that a famous DJ called uNo will be there and that she will tag Kurt in a photo.

Kurt picks up Kris and takes him to the club before trying to get uNo to tag him on a photo of him she took only to learn from his viewers that she’s lying. Kurt storms out and buys a ticket to Jessie’s show before being asked by uNo to take her to a taco truck and she promises to tag him in a photo if he does. While waiting for Kurt to get her some food from the truck, uNo discovers Bobby’s gun and poses with it on a Livestream before drinking some of the poisoned water and passing out. Realizing what has happened upon his return, he attempts to drive away but is stopped by two police officers who grow suspicious of him and it is revealed that Kurt’s murders have been discovered by the public and an unknown Kurt is being called “The Rideshare Killer.”

While Kurt is being talked to, uNo wakes up and panics, shooting dead one of the officers before fleeing, pursued by the second officer. Kurt takes advantage of the chaos to flee but is pursued down the highway by police. He escapes and crashes while live streaming, destroying his car. With Kurt’s murders becoming more well known, Spree is shut down. Jessie performs her show, performing a bit about her encounter with Kurt and how disgusted she is by people’s desperation for social media fame. Her speech goes viral and after getting drunk, is picked up by rideshare app GoGo. Kurt is revealed to be the driver, having killed the previous driver and live-streaming his drive with Jessie. Kurt unsettles Jessie who tries to escape after learning he is taking her to his house.

Unable to get out of the car, Jessie strangles Kurt with a phone charger causing them to crash but Kurt recovers and beats Jessie unconscious. He arrives at his house and places Jessie’s unconscious body outside before being requested by his viewers who now love him to kill Jessie. Distracted by a faulty camera, Kurt doesn’t notice Jessie has woken up and she manages to take control of the car. She crashes into Kurt’s house while trying to run him over and Kurt flees into the house. Jessie is confronted by an intoxicated Kris and the pair discover the dead body of Kurt’s mother who he killed at the start of his live stream. Kurt shoots his father dead and tries to kill Jessie but she pins him to the wall with the car, killing him.

Jessie becomes a nationwide star after taking credit for disrupting Kurt’s rampage while Kurt and his massacre become worshiped in small corners of the internet.