One week after the tragic suicide of Rose Cotter, ex-police officer Joel finds himself entangled in the harrowing grip of the Smile Entity. In a desperate attempt to transfer its curse, he confronts a pair of criminals at their hideout. However, a shootout erupts, resulting in the demise of both criminals, witnessed only by the drug dealer Lewis Fregoli. As chaos ensues, Joel attempts to escape but tragically meets his end, fatally struck by a truck.
In the heart of New York City, successful pop star Skye Riley gears up for her much-anticipated comeback tour, following a highly publicized struggle against substance abuse and the traumatic loss of her boyfriend, Paul Hudson. Under the strict watch of her mother and manager Elizabeth, alongside their assistant Joshua, Skye decides to sneak out and visit Lewis after injuring her back during rehearsals. However, upon her arrival, she witnesses Lewis's alarming behavior as he succumbs to the curse, bludgeoning himself to death with a weight. Traumatized, Skye opts not to contact the authorities, fearing the repercussions of being linked to Lewis's drug dealings.
As Skye embarks on her preparations for the tour, the specter of the Smile Entity begins to haunt her with vivid hallucinations of grinning faces, coupled with a series of inexplicable occurrences. Music executive Darius invites her to a charity event, which Elizabeth pressures her into attending. In the wake of rekindling a friendship with her estranged best friend Gemma, nightmares of Paul's demise plague Skye. An anonymous texter warns her of impending danger, sending her into a spiral of anxiety. At the charity event, Skye finds herself in a humiliating situation, inadvertently injuring an elderly patron while seeing an unsettling apparition of "Paul" smiling back at her.
Seeking answers, Skye meets Morris at a bar, a nurse who has been tracking the entity after losing his own brother to its curse. He explains the grim truth: the only way to rid oneself of the curse is through murder. Morris proposes a chilling solution involving killing and reviving Skye, but overcome by panic, she flees his grasp. Soon after, she faces a terrifying encounter with the entity, which disguises itself as her background dancers, leading to a concussion. Flashbacks reveal Skye’s guilt over the argument with Paul that led to the fateful car crash, which she regrets deeply.
Eventually, she finds herself in a wellness facility, clashing with Elizabeth over her erratic behavior. The horrifying realization dawns upon her that the entity is impersonating Elizabeth, who seemingly takes her own life with a shard from a mirror. In a desperate bid to escape the curse, Skye seizes a gun from a security guard and flees the facility. Reunited with Gemma, who helps her make a getaway, Skye receives further guidance from Morris about their next rendezvous, but a phone call from Gemma reveals the dreadful truth: the entity has assumed her form.
Meeting Morris at an abandoned pizzeria, he prepares to stop Skye's heart for eight minutes to ensure that the entity is gone. In a fateful turn of events, the entity attacks her, overpowering Skye and trapping her in a freezer instead of allowing her to end the curse.
As the night of her tour's opening arrives, Skye finds herself on stage, only to be confronted by a horrifying version of herself. Resigned to her fate, she allows the entity to invade her, collapsing as it takes control. The now-possessed Skye rises and horrifyingly stabs herself with a microphone, thus passing the curse on to Darius, Joshua, a still-alive Elizabeth, and the horrified audience witnessing this gruesome act.
