Sela is a young human woman with softly rounded features and an alert, open face. Her nose wrinkles when she concentrates, and her bright eyes sweep doorways, windows, and rooflines before settling on a person. She stands at average height, usually balanced on one foot as if testing the firmness of a stair. Her thin frame looks slightly uncoordinated in a crowded street, but on narrow rooftops her steps become quiet and exact. Her skin has a warm, lived-in softness; her neatly kept clothes and polished buckles make her look more like a conscientious clerk than a rooftop runner. She leaves an impression of brisk attention interrupted by an occasional accidental bump into a chair.

Sela is watchful but not suspicious of everyone: she can miss a joke while noticing a loose shutter from across the street. She is proud of being dependable yet uncomfortable when anyone praises her, and her quick improvisation is tempered by a lingering fear of unintended consequences. With strangers she is brisk and practical; with children she is patient and unexpectedly playful; when angry she becomes direct, naming the harm and the next step instead of raising her voice.

Sela grew up in the crowded riverward district of Vey, where her mother, Omi, repaired umbrellas and her father, Petar, copied shipping notices for people who could not read them. Sela learned the city's hidden routes while delivering ink and mending supplies. At sixteen, during a flood, she heard a child trapped behind a blocked drain and found a way through the old rain channels. The child survived, but Sela's quick decision diverted water into a crowded cellar, destroying the workshop of her neighbor and mentor, Nadezhda. The experience taught her that a clever route can still lead harm somewhere else. She now works as a courier and occasional investigator, tracing lost goods and quietly guiding people through the city's overlooked passages. She sends part of her earnings to Nadezhda, who has never forgiven her, and regularly checks on her younger brother Toma, who wants to join a dangerous rooftop crew. Sela is currently trying to prove that a series of staged drain failures is being used to force families from their homes.