A square, 1024x1024 image for an audiobook cover. The visual style should be a dark, atmospheric realism, evoking a sense of foreboding and rural decay. The central imagery is an old, isolated watermill, its wooden structure weathered and slightly dilapidated, set against a stormy, bruised twilight sky. One of the millstones is partially visible, hinting at a grinding, inescapable force. Subtle, dark green and brown hues dominate the palette, with shafts of weak, diffused moonlight piercing through the heavy clouds, casting long, distorted shadows. The overall mood is melancholic, tense, and slightly eerie, suggesting a hidden darkness beneath a veneer of apparent prosperity. The composition should feel grounded and dramatic, with the mill as the dominant focal point, emphasizing isolation and a palpable sense of impending doom. No text, no letters, no words, no title, no author name.