This is a highly styled 'genre' film which can perhaps be seen as a pastiche of all gangster movies.
Tom Reagan (Gabriel Byrne) is the terse advisor to a crime boss called Leo (Albert Finney). Leo is the boss of an unnamed Prohibition-era town where the police are pawns, and the periodic busts of illicit drinking establishments are no more than a way for one gang to get back at the other.
When Leo and rival boss Johnny Caspar (Jon Polito) feud over a bookie who's been cheating Caspar, Tom tries to keep the peace.
Instead he finds himself caught in the middle of a war of ambushes and shifting allegiances where nothing is ever quite what it seems.
This amoral tale which is also, paradoxically, a look at morals within the criminal underworld of the 1930s.