Population 436 is a thriller about a census worker named Steve Kady(Sisto) who is sent to investigate why the town of Rockwell Falls' population has been stuck at 436 for
Census Worker Steve Kady with Mayor Grateman
over a 100 years. When he gets to town he soon discovers that the town is almost too perfect. It is a town where everybody he meets greats him by name with a smile. A town where Deputy Bobby Caine (Durst) claims to have never had a murder and you can trust the town's people. He soon discovers that the town's happiness comes at a price and that is the population of Rockwell Falls must remain at 436. Kady and Deputy Caine soon becomes what the deputy refers to as friends.
Soon after arriving Mayor Grateman informs Kady that while completing his census questionnaires for the town that he can stay with Courtney Lovett and her mother. Courtney begins to talk about the outside world and what it is like. When Kady discovers a small girl named Amanda seems to be held against her will at Dr. Greaver's place he begins to investigate why. The town's people start telling him that people in town get a "fever" and that only Dr. Greaver's treatment can help them. At about the same point in the movie Kady begins to run into some of the people that Dr. Greaver has helped and they are referred to as being slow or not the same but everybody is grateful to the doctor because they keep saying it could be worse.
Kady with love interst Courtney
While investigating he begins to question Courtney who informs him that the "fever" is actually just what they refer to people as who want to leave Rockwell Falls. Soon Kady and Courtney begin a relationship and develop a plan to leave town. She warns him though that the nobody in town can know their intentions or they will treat them for the "fever".
When Kady attends a festival that has been planned since arriving in town he observes the festival's planner is standing with a noose around her neck and that she is not only willing but seems to be happy about killing herself to keep the population at 436. When Kady sees this he looses it and calls the town insane and tries to run. However his caught and taken to Dr. Greaver's for what is the first phase of treatment. When he wakes up back in his bed he takes off running only to run into another outsider who was taken in by Rockwell Falls. He informs Kady that he has to blend in and act like he wants to stay even if he doesn't. When Kady asks the other outsider why he stays he tells him that people that try to leave that all of them die in a strange way.
Population 436 makes many references to the classic short story "The Lottery". This is especially obvious when the citizen that is to be sacrificed to keep the population at 436 is drawn from a box with slips of paper where each resident has placed their name.