A dark, atmospheric, and gritty illustration in the style of early 20th-century French art, reminiscent of Gustave Doré or Honoré Daumier, but with a more painterly texture. The central focus is a powerful, stylized silhouette of a steam locomotive emerging from a tunnel of dense, smoky darkness. Wisps of dark smoke curl around the locomotive, hinting at danger and raw power. In the foreground, subtle, almost ghost-like outlines of human figures can be discerned, conveying a sense of their vulnerability against the mechanical might. The color palette is dominated by deep charcoals, sepia tones, oppressive blacks, and hints of muted, industrial ochre or rust. The composition should evoke a sense of claustrophobia and relentless forward momentum, with strong contrasts between light and shadow. The overall mood is brooding, intense, and somewhat foreboding. Square aspect ratio, suitable for an audiobook cover.