Gary Oldman plays a police sergeant named Jack Grimaldi who has a sideline in corruption and infidelity. His vices inevitably land him in trouble, but the Noirish setting is only half of the story - it's the performances of the cast that make Romeo as good as it is. It goes without saying that Oldman can be fantastic, but just as good was Lena Olin, an actress who held her own as an over-the-top femme fatale with an edge more deadly and unpredictable than most. Annabella Sciorra got less screen time but was also on top form.
It loses some of its momentum in the last third, but there's more than enough threads and ambiguity left to keep fans of this kind of drama happy.