Legend has it that during the shooting of The Big Sleep (1946) no one
could remember whether a certain character had committed suicide or
had been killed (and if so, by whom); so they sent Chandler a
telegram, and he couldn't remember, either. The story is absurd, yet
plausible: there is a Ponzi-scheme side to film noir, where long-term
logic is routinely sacrificed to immediate effect. And it works: one
is never bored, with these films; it's only at the end, when the
intrigue collapses like a castle of cards, that you feel a little
disappointed -- a little betrayed. But after all, betrayal becomes the
noir.