If you want three strongly persuasive reasons to watch, or revisit, this 1941 film noir classic directed by John Huston, who co-wrote the screenplay with original author Dashiell Hammett, here they are: Humphrey Bogart, Sydney Greenstreet, and Peter Lorre. Oh, Mary Astor’s important too, but it’s that terrific trio that really enlivens this marvelous mystery movie.