Short and compact with quick, deliberate movements. Serru wears layered furs that look patched but precisely arranged so each layer can be removed or offered without fuss. His cheeks are weather-burned and freckled. He keeps a needle-stitched ledger tucked under his left arm at all times with a brass corner plate engraved with the Thornbridge sigil. His smile is immediate and small, revealing a chipped front tooth he never mentions. He wears a narrow leather strap across his chest from which hang a brass whistle, a tiny lamp, and three different keys. Contradictory detail: despite his meticulous ledger and orderly bearing, his right sleeve is permanently dusted with a faint smear of white chalk as if he never quite finished marking something.