In 1977, a car salesman, Lou, goes from ordinary small-town citizen to FBI informant infiltrating the mafia when a key member of organized crime offers to buy his Cadillac dealership. Over the next three years, Lou finds his quest for glory tested when he becomes embroiled in the inner workings of the crime family – from fronting a multimillion-dollar operation, to becoming a surrogate son – before procuring the first-ever conviction of an infamous crime boss.