Sarah, portrayed by Madelaine Petsch, and her friend discover an old Polaroid camera among her late mother's belongings. After her friend receives a "like" from her crush, Sarah, feeling bold, snaps a photo of herself in lingerie using the camera. However, when she looks at the photo, she becomes uneasy as a chilling shadow looms in the background. After her friend departs, Sarah is left alone at home, where she investigates strange noises from the attic. In a moment of horror, she finds herself dangling upside down before being pulled up by a mysterious entity, ultimately leading to her offscreen demise.
The story progresses with a shy high school student, Bird, played by Kathryn Prescott, who receives the same Polaroid camera from her co-worker Tyler. This camera, bearing the initials "RJS," quickly becomes a source of terror. After taking pictures at a costume party, including a shot of her crush Connor (Tyler Young), Bird begins to notice a disturbing shadow appearing in the photos. Tragedy strikes when Tyler is murdered by the entity, sending shockwaves through Bird’s life. She later learns that the ominous shadow has shifted to Avery's photo, only for Avery to meet an even grimmer fate.
As Bird desperately attempts to protect her friends, she discovers a sinister pattern tied to the camera's history. The entity, manifesting the horrors of its past, is linked to a photography teacher named Roland Joseph Sable, who had a dark reputation involving the tragic fate of several students. Amidst the chaos, Bird and her friends fight against the entity, which has its own rules concerning photographs and heat sensitivity.
As events escalate tragically, including the death of Bird's friend Mina, the group gathers information about Roland's family's role in the camera's curse. They meet Lena Sable, Roland's wife, who reveals the heartbreaking story of their daughter, Rebecca, the original owner of the camera. Driven to madness by her bullying and the gruesome fate of her classmates, Roland's vengeful spirit now hunts those connected to his trauma.
With danger closing in, Bird and her allies confront the entity, learning about its ties to Sheriff Pembroke and the violent past that endangers their lives. Utilizing their newfound knowledge, Bird devises a plan to trap the entity and finally put it to rest. In a climactic showdown, she takes a daring risk to lead the entity into a spot where it can "fully develop." Through quick thinking and bravery, she confronts the monster, resulting in a fierce battle that claims the entity's existence. Ultimately, she unites with her friends and disposes of the cursed camera, ensuring that its dark legacy is buried forever.
