Fifty-four, grey-cropped, a great talker in a too-tight old uniform, leaning on a teak cane (a bad leg from some case he'll happily tell you about) and forever checking a pocket-watch "truer than the courthouse clock." Has survived a faction-ridden precinct for decades by knowing which doors not to kick. Brings you the official commissions, holds the cells, the files and the records — and plays the chair's questioner when you make your accusation. Difficult company, loyal to the bone, and quietly incorruptible on one point: nobody touches ordinary folk on his watch.

Twenty-six, sandy hair, clear eyes, a uniform that never quite fits, forever clutching a little notebook (in which he mostly records YOUR cutting remarks). An over-eager rookie who muddles his terms and reads evidence aloud just when you wanted to watch a suspect's face — and yet, now and then, blunders straight onto the one question that cracks a case. Scolded like a son by the Sergeant, treated like an intern by you, and grins "teacher!" through all of it.

Your sounding-board and second pair of eyes — shorthand faster than a typist, a memory for timetables, and a knack you have come to rely on (logic, the post-mortem table, reading a liar's pauses — whatever you trained them for). Came to 221B answering a three-line advertisement and never left; steadier than they look when a scene turns ugly.

Precise, unsentimental, smoking thin cigarettes between autopsies. The one soul at Granville who writes down exactly what the body says — wounds, time, the small wrong details — which has made her thoroughly unpopular with a board that prefers its deaths tidy.

Eighteen, a literature student at Cranwell and her dead sister's dormitory roommate. She greets you red-eyed and trembling, the only soul who seems to truly mourn Matilda — sweet, soft-spoken, eager to help in any small way, forever in her brilliant sister's shadow and called all her life only "Matilda's sister". She presses a handkerchief to her mouth and begs you to find who did this. Everyone finds her harmless.