Teen boy in skeleton suit walking through dark sewer tunnel

A dimly lit, ancient sewer tunnel deep beneath the city. The walls are old, dark brick, slick with moisture and streaked with grime. A shallow channel of dark, sluggish water runs along the floor, reflecting faint, flickering light from a single, rusted grate high above. The air is thick with shadow and the suggestion of decay. A thirteen-year-old boy, tiptoes cautiously through the tunnel. He is slender, tall, and athletic, dressed in a fitted black outfit printed with an ultra-realistic white skeleton across the front and arms. His youthful face obscured by a black hairy mask, but his dark, watchful eyes are visible, scanning the darkness ahead. His posture is coiled and alert, one hand resting near a hidden tanto at his waist. The atmosphere is one of claustrophobic dread, Gothic horror, and quiet, lethal vigilance. Style: dark, realistic with moody, cinematic lighting, deep shadows, and a single source of pale, sickly light from above, creating long, distorted shadows on the wet brick.