A milkman makes a delivery and when he notices the last delivery wasn't picked up he goes inside to investigate. He finds his customer murdered. When he hears a noise upstairs, he goes to investigate and finds something that shocks him: Siamese twins Bette and Dot Tattler. They are taken to the hospital where Elsa Mars sneaks in to see them. She questions them, including about their sexual experience. The twins are able to communicate without speaking. They share some organs like their reproductive system, but have 2 hearts.
A guy and a girl are on a picnic. He doesn't want to go all the way because he doesn't want his girlfriend to get pregnant. She has condoms. He goes to the car for something and she's approached by a clown who gives her flowers. When her boyfriend comes back, the clown beats them and kills the boyfriend and goes after her.
Elsa Mars is at a diner and approaches Jimmy Darling. She was able to keep the location and wants to expand the show. He believes she's delusional. They aren't wanted there any more. After 2 months, they were kicked out of the land even though they had a year lease. Not enough people have been showing up and a revival wants to use the land. Elsa seduced the land owner to get another month out of him. Jimmy says it's over, but she has a plan. She believes she's a "star."
Jimmy has other plans. He's been using his misshapen hands to pleasure women for money.
The clown has been on a killing spree. He kept the girl from the picnic and abducted a kid. The clown keeps them locked in a small section of his trailer. He starts to perform for them, but when a balloon pops he goes ballistic and starts throwing things at their cage.
The twins left the hospital and Elsa Mars goes to find them at home and accuses them of murder. They admit what they did and Elsa says she wants to help them. She brings them to the Freak Show. One of the twins is happy at the show, while the other is miserable. The bearded lady brought them dinner and encouraged them to appreciate Elsa's gift of a place to live as themselves.
The Candy Striper wants to leave and Elsa tells her to go then but not to mention anything that goes on there. When the Candy Striper threatens to out them, Elsa shows her a film of all the degrading things she did while high. When the Candy Striper says the people there are monsters and depraved, Elsa replies that those outside are the monsters.
Jimmy wants to get out and have a normal life. His mother says that there isn't a normal life for people like them. She encourages him to visit the twins to try and get them to eat. Jimmy finds the detective in the tent with the twins and accuses them of killing their mother and the other deaths too. He wants to arrest them, but other freaks show up to block the detective from taking them. Jimmy slits the detective's throat when he calls them freaks.
Gloria and Dandy Mott show up to watch the show. It was an elaborate stage production for two people in the audience. Dandy Mott visits the twins after the show and wants to buy them. They offer $5,000 and up to $10,000 for both of them. Elsa pushes for more money and they offer $15,000. The twins don't want to leave now that they've found a family.
The clown shows up on the merry go round. The freaks go with Jimmy to bury the detective. He wants them to band together to take on those who look down on them. They all hatchet the detective as the clown looks on.
Elsa admits to Ethel she brought the twins there not to save the show but so people would come to see her so she'd be discovered to be a star. Ethel says that Elsa will become a household name which makes her feel better. Elsa removes her fake legs.