During Thanksgiving in Plymouth, Massachusetts, people are gathering outside the local RightMart superstore in preparation for a Black Friday sale. Jessica Wright, whose father Thomas owns the store, lets her boyfriend Bobby and her friends Evan, Gaby, Scuba, and Yulia inside the store early through a side door. The crowd outside sees them and, in a frenzy, stampedes into the store, resulting in multiple people dying, including Amanda Collins, the wife of store manager Mitch. Bobby gets his arm broken when he tries to rescue someone and subsequently disappears from the group.One year later, RightMart is preparing for another Black Friday sale, despite the protests of Mitch and several other residents. Meanwhile, Jessica and her friends are tagged in a social media post of a Thanksgiving table with their names around it. Bobby, who has broken up with Jessica, returns to Plymouth to work for his uncle after being injured in the riot, much to the chagrin of Jessica's current boyfriend Ryan. A waitress named Lizzie is attacked and killed by a figure dressed in black clothing wearing a John Carver mask. The police discover that Lizzie was present at the Black Friday incident, which leads them to believe those involved in the massacre are being targeted by Carver.Jessica aids the investigation by providing footage of the riot to the town's sheriff, Eric Newlon. Carver rampages through Plymouth and kills several residents, including RightMart security guard Manny and high school students Amy and Lonnie. Evan and Gaby are soon abducted by Carver, while Jessica narrowly avoids being killed. Yulia's father decides to move their family to Florida, but he and the deputy sheriff guarding them are knocked out by Carver before he attacks Yulia. Jessica and Scuba drive to Yulia's house, but are unable to stop Carver from disemboweling Yulia with a buzzsaw before he escapes.The police attempt to lure Carver out by having the Wright family and Scuba participate in a Thanksgiving parade, disguised as Pilgrims. However, Carver deduces their plan and decapitates a turkey mascot before sending smoke bombs into the crowd, causing everyone to scatter in panic and giving Carver the opportunity to abduct the Wrights and Scuba in the chaos. Carver then cooks Jessica's stepmother Kathleen alive in an oven before serving her as the "turkey" at a dinner table surrounded by his hostages and his victims' corpses. Carver then bludgeons Evan to death in a livestream before Jessica cuts through her bindings and escapes, luring him away from the others. She eludes Carver by climbing over a fence and running through the woods. Jessica makes it to a parade warehouse, and finds Newlon unconscious. When she follows a figure wearing Carver's mask inside, she sees it is Bobby. She calls Newlon to help capture Bobby, but he escapes.The police soon arrive and inform them that the survivors are safe. Once they leave Jessica and Newlon alone, Jessica notices the same bramble debris from the fence and the deep woods that stuck to her are also on Newlon's clothing and sneakers, realizing he is the killer. Newlon reveals that he was having an affair with Amanda, who was pregnant with his child before she died. This was his motive to become Carver and seek revenge on those responsible. Newlon had abducted Bobby and put him in the Carver costume, intending to shoot Bobby and frame him for the murders. To Newlon's horror, it is revealed that Jessica has livestreamed his confession, leading him to attack her until she is saved by Bobby.As they attempt to escape in a tow truck belonging to Bobby's uncle, Newlon hooks it to a support beam and approaches them with an axe. Jessica uses a musket to shoot a turkey parade balloon that was attached to a tank of flammable gas, causing an explosion that engulfs Newlon in flames. The following morning, Bobby is taken away in an ambulance and Jessica reunites with Ryan, Gaby, and Scuba. The authorities are unable to find Newlon's remains, leading them to believe he was incinerated in the explosion. However, Jessica continues to have nightmares of a flaming Newlon attacking her.