The 'Southland Dog Killer,' who previously killed only pets, murders online beauty influencer Genelle in the bathroom during a cosmetics promotion. In light of events, social media star Mia Larson cancels her livestream plans with friends Lani, Jade, and Santi to watch her sister Nicole's dog Chico instead. Meanwhile, Nicole supposedly travels to San Francisco to undergo treatment for Livingston's Disease, a hereditary brain condition that killed Nicole and Mia's mother.While ignoring Chico, Mia repeatedly receives unsettling texts and phone calls from Nicole's neighbor Kellan. Using disturbing videos, Kellan reveals he kidnapped Nicole, Mia's friends, and Chico. Kellan proves he will torture Mia's friends if she tries to leave or call the police. Kellan forces Mia to answer questions, perform tasks, and make choices between who lives and who dies as part of a sick game. Chico seemingly dies when Mia chooses Lani over the dog. Mia also chooses Lani over Nicole.Lani finally calls Mia and explains that everything was an elaborate prank that Lani livestreamed to Mia's followers. Lani reveals she is in the attic, Jade and Santi are in a vacant house next door, and the real Kellan was never involved.Mia becomes incensed by everyone's callousness, particularly when she discovers Lani exploited footage of Nicole crying at their mother's funeral. Her newly shaken mental state compels Mia to call her sister and apologize for abandoning Nicole to care for their dying mother alone.Lani calls back with a warning that someone else is in the house, which Mia doesn't believe. Someone kills Lani. Santi calls to tell Mia he is locked inside the other house. Fed up with the apparent prank and unable to find her stolen keys, Mia calls a rideshare and is paired with a driver named Big Mike.Mia realizes it is no longer a prank when she finds Lani dead in the pool. Someone identified as Kellan texts Mia and forces her to give herself painful injections. Mia finds Santi suffocated.Jade calls Mia. Jade claims Lani paid her and Santi a lot of money to participate in the prank. However, Kellan sends a video proving Lani was actually broke and worked at Whole Foods, and only pretended to be posh online.Mia finds her mother's corpse in a closet. Nicole enters the house to reveal she was behind everything all along, including the initial setup with the dog deaths. Nicole explains that she tormented Mia because she felt her sister was selfish when it came to their family, which was additionally proven by Mia ignoring the dog and choosing Lani over Nicole.Nicole shows a video proving she smothered their mother on her deathbed. Mia tries telling Nicole that she suffers from the same mental sickness that runs in their family.Nicole threatens to stab Jade unless Mia breaks her legs. Mia bashes one of her legs with a baseball bat and tries breaking the other by jumping over a banister. Nicole kills Jade anyway.Nicole lies on the floor beside her sister. Nicole accuses Mia of presenting a false personality online, and says she never believed Mia would care for her like Mia once promised.The real Kellan comes to the front door. Nicole shoots Kellan when he gets suspicious.Mia uses the opportunity to turn the tables on her sister. While their confrontation continues livestreaming to her followers, Mia knocks Nicole unconscious. Mia limps outside and collapses on the sidewalk. Having pulled up in his car, Big Mike asks if she is Mia. Mia replies, "No." Livestream viewers see that Nicole is still alive.(copied from culturecrypt)