Fifteen-year-old Heidi is just starting her sophomore year of high school when the summer's string of gruesome murders begins to take effect on her life. Only two days into the new school year, she's hit with the news that shatters everything: her childhood best friend, Bonnie, has gone missing. Overwhelmed but determined, Heidi is ready to search for answers until her own little sister disappears, too. Her entire family is devastated. Forced into detective mode, Heidi teams up with her loyal friend Ryan, while her other friend Vickie is nowhere to be found. Her tight-knit friend group of 4 begins to crumble. Strange, cult-like videos are circulating on social media from a mystery page advertising blood rituals and young teens who are being killed with no suspect in sight. And while Heidi desperately searches for the truth, strange events are happening around her that she doesn't yet understand. Because someone close to Heidi isn't who they seem. Someone is lying. Someone is hiding. Someone she trusts... might be a killer.