Oh, the caveman episodes are where you really see the characters begin to develop, I think. Not just Barbara, but we even get to see the Doctor, who's first impression is a crotchety, suspicious old man (not without reason, I've always maintained, what with people busting into his house and all) to someone who can feel and express genuine fear and panic. Ian, too, shows up as more heroic as the serial progresses, I think. Kind of neat!

Barbara's hair must be fantastic on a windy day, the way it holds it's shape.