New Year, New You

Alexis and the child she babysits watch a video featuring Danielle Williams, a social media influencer with her own streaming television show and a former friend of Alexis. Later, Alexis returns to her house to prepare for a New Year's Eve party with her high school friends Kayla, Chloe, and Danielle. However, Danielle's arrival causes tensions to mount, until Alexis lashes out at Danielle for saying she never drove a girl named Kelsey to suicide. As Danielle attempts to shift the conversation, Alexis waterboards her with champagne, counts down to midnight, and then tells the other girls to tie Danielle up like they all agreed to.
With Danielle tied up, Alexis berates her for bullying each of them, then reveals she intends to sabotage Danielle's career by recording her confessing to her role in Kelsey's suicide. When Danielle avoids accepting the blame for the bullying, Alexis violently messes up Danielle's face and hair to make her more "camera-ready." Kayla, overwhelmed, leaves the room to FaceTime her girlfriend, Frankie. Alexis follows Kayla, and Danielle convinces Chloe to free her by offering Chloe her spot on the YouTube channel she will be leaving. When Alexis and Kayla return, Danielle knocks Alexis out.
Danielle and Chloe lock Alexis and Kayla inside a sauna, intending to wait until they die before calling the cops to make the deaths seem accidental. Alexis and Kayla discover a champagne bottle and, using it to smash the sauna's window, nearly escape but run into Danielle and Chloe. They hide in Alexis's closet before Alexis leaves to find her phone, leaving Kayla alone. Chloe finds Kayla, who tries to convince her to walk away and keep everything secret, but she claims Kayla doesn't want her to succeed and accidentally kills her. Meanwhile, Danielle corners Alexis and cuts her calf, but Alexis gets away.
A shaken Chloe comes down to meet Danielle while Alexis tends to her wound. Frankie arrives looking for Kayla because she didn't answer her phone, and Danielle and Chloe decide to frame Frankie and kill her. After watching Chloe violently stab Frankie, Alexis runs upstairs and prepares to defend herself. When her ex-friends give chase, Alexis knocks Chloe down the stairs, killing her. Danielle then engages Alexis in another fight, only for Alexis to throw Danielle out of a window to her death in the pool.
Later on, an influencer who worked with Danielle discusses how Frankie killed Danielle after Danielle encouraged Kayla to end the relationship. Alexis stands next to her, and, after taking a moment to "grieve", she immediately becomes bubbly and films her video, happily that she now has Danielle's life.