Create a moody autumn painting of a hidden railway track leading into an old stone tunnel, its arch draped with ivy and moss. The evening rain falls gently, coating the ground in a glossy sheen. A dim lantern glows on a post, its light blurred by the mist. The forest surrounding the tunnel is alive with golden and crimson leaves, while far above, the dark outline of mountains looms silently. The whole scene feels like the beginning of a long-forgotten story.