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.

Forty-eight, immaculate in a velvet-collared coat, the West End's smoothest impresario — and this morning a man whose star has died on his stage the day after the triumph of his career. He frets aloud about the box office, the board and the papers, and rather less about Rosalind herself. Helpful, anxious, and forever steering you toward the tidiest possible answer.