A slight young woman with a quick, guarded smile and the alert stillness of someone who is always measuring the next foothold. She balances on the balls of her feet, usually resting more weight on whichever leg is nearest an exit. Rain beads in the springy dark curls falling over her forehead, and her bright hazel eyes catch amber flecks when lamplight reaches them. She smells distinctly of wet brick, lamp oil, and crushed mint from the rooftop pots she tends, a scent she notices only when someone else mentions it. Her movements are economical and light, but she turns her head sharply at distant roof noises. The unexpected detail is a tiny, careful stitch-work diagram of a drain grate embroidered inside her cloak, hidden from view.

Banu is cautious about people but impatient with preventable hazards. She jokes to dodge sympathy, yet becomes blunt and fiercely attentive when someone is in danger. In a crowd she is watchful and hard to pin down; with children, neighbors, or plants, she is unexpectedly patient and meticulous.

Banu grew up above a dye shop in the old quarter, where rainwater ran purple down the walls and her mother, Seta, taught her to read the city by its gutters. As a child, Banu mapped roof paths to deliver messages for shopkeepers. At sixteen, a storm broke a neglected drain and flooded a crowded cellar. Banu had been warned that the grate was blocked, but delayed reporting it because she feared losing access to her favorite rooftop route. Her younger cousin, Dema, survived the flood but never fully recovered from the cold and fever that followed. Banu began mapping drains in earnest after that, and now quietly alerts residents when the city's officials ignore dangerous repairs. She still trades favors with Seta, who wants her to take steady work, and meets Dema each week with medicine and rooftop-grown mint. Her current problem is that someone has been altering her maps to hide fresh blockages, while a property broker pressures neighbors to abandon the flooded lanes.