Thalia is a severe, impeccably neat Tidewise Human with a narrow, intelligent face and a posture so straight that she seems to be balancing an invisible ruler along her spine. Her slate-gray hair is pulled into a tight professional knot, though one rebellious silver strand always escapes above her left ear. Her dark eyes remain sharp behind wire-rimmed spectacles whose lenses are faintly scratched by years of salt air. She moves in short, economical steps, never hurrying and never yielding space, making crowded docks part around her like water around a piling. Her hands are ink-stained at the fingertips but otherwise immaculate. The unexpected contradiction is that her intimidating presence is accompanied by a soft, almost tender habit of humming children's counting songs while examining evidence.