It is ten years since the slaying of five cheerleaders in a small town. The one cheerleader that got away is back in town and staying with her mother. Elliette Oliver has flashbacks to her friend's murders, and she hides her pom-poms in a dresser drawer to stop the memories.Ellie is a new teacher at the school, and the students are fascinated with her and ask inappropriate questions. Ellie's classmates still work at the school, specifically a jock named Forrest Parker, who was dating one of the murdered girls, and he married her twin sister Brooke. Ellie volunteers for the open position of cheerleading coach. At practice, she is surprised to see the squad is just four girls, they don't have uniforms, and they don't do stunts. The girls don't even want to be there.Ellie's mom set her up on a date with her doctor, Jon. They were classmates in high school too. On their date, Jon admits to having the biggest crush on her in high school. They decide to go on a second date.The next morning Ellie goes for a run on the track in a windbreaker. The workout is cut short when she finds a cheerleader tied to a pole with "I'm Back." Written in blood on her shirt. But it was revealed that she's not dead and the blood on her shirt is pig's blood.It is ruled as a prank, and Ellie is finally put into therapy. The red-headed therapist wants to put her into an immersion therapy and suggests journaling-multiple times.Chloe, Brittney, Pippa, and Ava talk with Forrest Parker, who just happens to have photos of all the dead bodies of the cheerleaders who were murdered on his work laptop. He freaks the girls out, and they quit the team. Well, everyone except Ava, who seems into it. Ava gets transcripts and works with Dillion (her boyfriend) to learn what happened ten years ago.With no team and lots of time on her hands, Ellie finds an old journal. The next day Brooke and Forrest have an informal reunion, and Ellie invites her new friend Lisbeth to join her.At the reunion, no one remembers Lisbeth, not even Jon, who dated her. Brooke runs into Ellie by the bathroom, asks what happened to her sister, and then blames her.Meanwhile, the teenagers are at the football game, and Pippa is missing. (Pippa goes to the washroom and is attacked by a masked man) Chloe is too busy sexting Forrest Parker to care. (Earlier, she slapped his butt in the parking lot, and he was into it.) Ava goes in search of Pippa and sees blood on the stairways which leads her to Pippa, who's stuffed in a locker. (Again, the blood seems to be pig's blood). The Sheriff suspects Ellie because someone stuffed her poms in Pippa's mouth. Also, her phone is missing again, so they can't track her whereabouts. Lisbeth finds the phone in the parking lot.Forrest pushes this affair with Chloe. He says, "Your grades are lacking in my class, so are we gonna do this?" Chloe doesn't even seem like she wants to have an affair, but she goes to his house in the middle of the night. She has second thoughts and goes back to her car. But before she could leave, a masked man seated in the back seat attacks her.Lisabeth and the students watch as the police drag Forrest away under suspicion of Chloe's disappearance. Then Lisabeth overshares about trying out for the cheerleading squad and not making it because she feels invisible. Then she goes to her classroom takes out her yearbook that confirms she is stuck in the past. (She has hearts around Jon and x's on the cheerleaders.)Ellie wakes up after drinking some wine with lipstick writing all over her mirror and walls that read, "I Did It." Ellie shows Jon, and he asks her if she did it. Then they find Chloe's headband in her bed. Jon thinks it could be a mental breakdown. Ellie realizes that it was Lizabeth. She finds Lisabeth's yearbook with all the writing in it. Then she drives to Jonathan's house to show him the evidence. Meanwhile the police has issued a open warrant for Ellie as her whereabouts are unknown. Ava sees Ellie getting into her car, follows her to Jonathan's house, and calls Dillon to meet her there with reinforcements. As Jonathan seems not to be in the house, Ellie sits on the balcony, suddenly has a flashback, and remembers the killer was Jonathan! Too bad for her; he is right behind her.Jonathan ties her up and admits to killing everyone because they laughed at him and put him in the friend zone. He framed Ellie for all the murders and has it all figured out. Meanwhile, Ava, Dillion and Pippa break into the house and finds Chloe tied up on the floor. She tells them that it was not Ellie who kidnapped her but the 'person upstairs.' They go up quietly and record Jonathan's whole confession with their phones. Ellie frees herself and hits him with a fire poker knocking him out cold. He is taken to jail to rot.Ellie's mom's cancer is in remission. They celebrate with champagne. The final scene is Ellie coaching the new cheerleading team, consisting of Ava, Pippa and others.