The Wild One

''This is a shocking story,'' reads a caveat at the beginning of The Wild One. ''It could never have taken place in most American towns — but it did in this one. It is a public challenge not to let it happen again.'' Moody Marlon Brando and a pack of bikers descend like a biblical plague on a California town and proceed to torch and terrorize it. ''What are you rebelling against?'' asks a townsman. ''Whaddya got?'' Brando replies. Brando's tight denims and defiance prefigured James Dean's archetypal rebellion. In black and white. B