Maddi's world shatters when her sister, Avery, mysteriously vanishes without a trace. Devastated by the loss, Maddi refuses to accept defeat and embarks on a relentless search to unravel the mystery behind her sister's disappearance. United with her loyal friends Sam and Maria, they plunge headfirst into a world of clues and questions that will test the limits of their determination and resilience. As they tirelessly investigate, a mysterious discovery within Avery's forgotten diary sends chills down their spines, revealing that the sinister culprit is closer than they ever imagined.