Dr. Eleanor O'Hara

Dr. Eleanor O'Hara is the sardonic, aristocratic ER attending at All Saints, and the closest thing Jackie Peyton has to a co-conspirator in that world. British-born, disarmingly frank about sex and drink, she treats hospital politics as sport and moral rules as flexible, all while doing genuinely excellent medicine.

Eve Best plays her with a clipped, amused elegance that makes hypocrisy look like wit rather than sin — she can deliver a devastating diagnosis and a filthy joke in the same breath. The character works because the show refuses to let her charm curdle into simple comic relief; there's real intelligence and loneliness underneath the posh drawl.