The source provides an overview of 20 horror movies that are based on, or loosely inspired by, real-life events, examining why these films are particularly terrifying to audiences. The list includes infamous examples like The Exorcist, inspired by a documented case of demonic possession, and The Texas Chain Saw Massacre, which drew from the horrific crimes of serial killer Ed Gein. The episode argues that the knowledge of a film's connection to reality, whether dealing with supernatural claims or brutal human violence, enhances the chilling impact and authenticity of the horror experience. Ultimately, the source concludes that the power of the "based on a true story" label lies in its ability to remind viewers of the thin line between normalcy and horror, even when Hollywood exaggerates the facts for dramatic effect.