A darkly atmospheric, psychological thriller book cover. The primary imagery is a lone, dimly lit window in an old, imposing apartment building, with faint, unnerving shadows visible behind the glass. A single, wilting potted plant sits on the windowsill, symbolizing fragility and decay. The overall mood is one of suspense, isolation, and unease. The color palette is dominated by deep blues, grays, and muted, desaturated greens, with a hint of sickly yellow light emanating from the window. The composition is tightly framed, focusing on the window as the central element, creating a sense of voyeurism and claustrophobia. The style should be painterly and photorealistic, with a texture that suggests age and dust. The atmosphere should be tense and foreboding, hinting at secrets and danger within. Aspect ratio 1024x1024. NO TEXT, NO LETTERS, NO WORDS, NO TITLE, NO AUTHOR NAME.