Thirty-five years after the shocking murder of three teens, the infamous "Sweet Sixteen Killer" returns on Halloween night to claim a fourth victim. Seventeen-year-old Jamie (Kiernan Shipka) ignores her overprotective mom's (Julie Bowen) warning and comes face-to-face with the masked maniac and, on the run for her life, accidentally time travels back to 1987, the year of the original killings. Forced to navigate the unfamiliar and outrageous culture of the 1980s, Jamie teams up with her teen mom (Olivia Holt) to take down the killer once and for all, before she's stuck in the past forever.