Margot Mills and her date Tyler travel by boat to Hawthorne, an exclusive restaurant owned and operated by celebrity chef Julian Slowik, located on a private island. The other guests attending the dinner are Lillian, a food critic; her editor Ted; wealthy couple Richard and Anne; George, a post-prime movie star, and his personal assistant Felicity; and business partners Soren, Dave, and Bryce, along with Julian's alcoholic mother. The group is given a tour of the island by the restaurant Maître d'hôtel, Elsa, who notes that Margot was not Tyler's designated guest for the evening.Dinner begins, and Julian introduces a series of courses, delivering increasingly unsettling monologues about each meal. As the night goes on, secrets about each guest, ranging from affairs to money laundering, are slowly revealed amidst dialogue satirizing class divides, climate change, patriarchy hindering women's success (and creating unreasonable expectations for men), and capitalistic exploitation, usually spurred by Julian and the staff's introductions and meals. During the fourth course, a sous chef kills himself in front of the guests, and another staff member cuts off Richard's ring finger when he tries to escape. After the fourth course, the restaurant's prime investor, and Soren, Dave and Bryce's boss, is drowned in full view of the diners. At various points in the night, Julian allows guests to attempt escape, only to have the staff catch and return them.Julian declares all the guests were selected because they either contributed to him losing his passion for his craft or because they make a living off exploiting the work of artisans and workers like him and his team. He announces that everyone present will be dead by the end of the night. Since Margot's presence was unplanned, Julian privately gives her the choice of dying either with the staff or with the guests. When Margot hesitates, Julian decides for her, saying he knows his upper-crust customers from fellow service-industry workers.It is revealed that Margot is an escort named Erin, who has been hired before by Richard (explaining them staring at each other all night), and who Tyler has hired for the evening. Julian reveals that Tyler was invited personally and knew all along that the dinner would end with everyone's death, so he invited Margot knowing full well she would die. Julian humiliates Tyler further by forcing him to cook and insulting his food, causing Tyler to kill himself in a storeroom. Julian asks Margot to collect a barrel needed for dessert.Margot sneaks into Julian's house, only to be attacked by Elsa. Margot kills Elsa in self-defense by stabbing her in the neck. After seeing newspaper clippings of Julian's past life in his office, Margot finds a radio, calls for help and returns to the restaurant with the barrel. A Coast Guard officer arrives from his boat, then reveals himself to be a line cook in disguise and returns to the kitchen.Margot mocks Julian's dishes and complains that she is still hungry. When Julian asks what she would like to eat, Margot requests a cheeseburger and fries, having previously seen a photo of a younger, happier Julian working at a fast-food restaurant. Moved by her simple request, he prepares the meal to her specifications. Margot takes a bite and praises his food, then asks if she can get it "to go". Julian packs the food for her, and he and the staff allow her to leave. Margot takes the Coast Guard boat docked nearby and escapes the island.The dessert is an elevated s'mores dish - the staff cover the floor with crushed graham crackers and adorn the guests with small capes made of marshmallows and hats made of chocolate. Julian then sets the restaurant ablaze, detonating the barrel and killing the guests, staff, and himself as Margot watches from the boat and unpacks her cheeseburger to-go.