Tressa Brass-Lock is a compact rock gnome woman with the immaculate precision of a surgical instrument and the restless energy of a wound-up clock. Her face is narrow and expressive, marked by a tiny burn scar that crosses the bridge of her nose beneath her spectacles. Polished brass glasses sit over pale amber eyes, each lens fitted with a rotating magnifying loupe. Her left arm moves with deliberate economy because a heavy mechanical support brace lies concealed beneath the sleeve, its internal pistons clicking softly when she lifts anything heavier than a ledger. Her fingers are blunt, nimble, and permanently darkened at the creases by soot that no solvent has fully removed. She walks with brisk, measured steps, never quite making a sound despite the weight of her equipment. The unexpected contradiction is that her spotless clothing and exacting manners conceal a ferocious mechanic's hands, while the supposedly disabled arm is often the strongest and steadiest part of her body.