So you have the blonde walking into the cynical detective's office. You have some "broad" in an evening gown singing torch songs in a club that's maybe on the edge of sketchy. You have probably some thugs somewhere, somebody covering up something horrible for someone they love.
What else have you got? What are your favorite stock elements for this kind of story? Tell me, that I may warp them!
(I'm heading down to St. Pete for lunch as soon as I get my shoes on, so I won't be able to respond to answers right away.)