When Clara Lewis moves into Apartment 4B, she wants nothing more than a quiet reset. But the apartment has a history-and a memory-of its own.At first, it's small things: a hairpin left on her pillow, footsteps in the walls, whispers that fade when she turns her head. Then she finds an old diary hidden behind peeling paint, its final pages written by a woman named Ella who vanished forty years ago. The last line ends mid-sentence.And then Clara hears someone finish it.Drawn deeper into the building's strange architecture, Clara discovers concealed passageways, shifting reflections, and recordings of her own voice-spoken when she was asleep. Her cameras capture someone inside her apartment who looks exactly like her. Her neighbor, Ben, knows more than he admits, and the elderly tenant across the hall warns her: "Stay out of the walls."But the walls don't stay out of her.As time begins to loop and the world outside loses its shape, Clara is forced to confront a terrifying truth: something in Apartment 4B wants to trade places with her. And it's already wearing her face.In the end, Clara must choose which reality to believe-and which version of herself to save. Two possible endings offer readers a chilling fork in the story's final path: one where the haunting is real, and one where the only ghosts are the ones she's been living with all along.