In a stark departure from the remote cabin setting of its predecessors, the story unfolds in the urban sprawl of a Los Angeles apartment building. Here, two estranged sisters, Ellie and Beth, reunite with the intent to mend their frayed relationship. Ellie's life is hectic with the responsibility of raising three children, while Beth arrives from out of town, seeking connection and a fresh start. The siblings' attempt at reconciliation is juxtaposed with the chaos of Ellie's crowded, life-filled apartment, painting a picture of family life that is relatable yet strained.

Amidst this backdrop of familial tension and everyday struggles, a horrifying discovery in the bowels of the building sets the stage for terror. The sisters stumble upon an ancient book that exudes malevolence, and unknowingly, they unleash a demonic force that is both relentless and insatiable. As the dark power begins to infiltrate their world, the familiar setting of their urban life twists into a nightmarish landscape. They are thrust into a fight for survival not only against the evil they've awoken but also for the soul of their fractured family. Ensnared in a battle where the lines between reality and the supernatural blur, the sisters must confront their own demons if they are to stand any chance against the malevolent entity seeking to consume them.