Follows a criminal gang in Rome that has a near monopoly of the city's heroin trade. Besides their internal feuding, the gang has to deal with the Camorra and Sicilian Mafia that both supply its heroin, the police led by Commissioner Scialoja and the Italian secret services.

Italian police inspector Coliandro — an ignorant, boorish, but fundamentally kind-hearted oaf, whose entire worldview is informed by American cop movies — protects the good citizens of Bologna, routinely saving the day and foiling the plans of evildoers of all sorts by a combination of dumb luck and genuine bravery, while always falling hopelessly in love with the woman at the center of the case.