Toy Fawn leads an ordinary life until her world is upended when her mother leaves for cancer treatment, leaving her alone. Seeking solace at her boyfriend's home, Toy's routine existence takes a sinister turn when they discover her friend's missing brother, Owen, hidden in the basement. Their attempt to rescue Owen leads them into the clutches of Kieran, the man who abducted him years earlier. Trapped in what they believe to be an abandoned asylum, Toy and her friends must confront a series of terrifying challenges, including an ancient plague, malevolent spirits, and Kieran's ominous presence. As her companions succumb to an inexplicable slumber, Toy grapples with her newfound role as the carrier's protector against a looming threat that imperils not only their lives but also the fate of their universe.