THE BIG COMBO represents both director Joseph H. Lewis and cinematographer John Alton working at the height of their respective powers.
Cornel Wilde stars as Lt. Diamond, a self-righteous young officer hell-bent on taking down mob kingpin Mr. Brown (Richard Conte) who is so powerful he never has to get his hands dirty, thus his record is squeaky-clean and is considered untouchable. Diamond is obsessed with Mr. Brown's girlfriend, driven by an apparent savior complex to "rescue" her from the sadistic kingpin. Yet Diamond's obsession extends to Mr. Brown himself - his need to knock him off his throne is motivated less by a desire for law and order, and more by a desire to get what he can't have.
Conte's Mr. Brown is a chillingly sadistic character - and also appealing in a very unsettling way. He humiliates and berates aging gangster Joe McClure (Brian Donlevy), and keeps his girlfriend an emotional prisoner. Brown is always one step ahead of the police and, when McClure attempts to take his own revenge against his sadistic boss, Brown is again one step ahead, reminding McClure who's boss by turning his own hired killers against him. The scene where Brown taunts Diamond by pointing out that he's everything that Diamond wants to be, but can't, sums up his appeal and power.
Brown is finally betrayed, allowing Lt. Diamond to turn the tables on him and reducing him to a scared, panicked wreck like a deer in headlights. But it feels inauthentic because Mr. Brown is simply a much more interesting character than the bland Diamond. Still, Lewis' direction plunges us right in to this cynical, topsy-turvy world and never lets up, aided by Alton's stylish cinematography that conjures up an appropriately shadowy atmosphere, resulting in some iconic imagery.