Elton "Mac" McCoy, a rookie US Marshal, must protect a small child from the Chicago Mob in a decade when the Mafia ruled the streets, the police, and City Hall.

Six-year-old Cianna, the sole witness to her family's murders, carries the burden of testifying against the powerful and charismatic Mob boss, Ray Lombardo.

Lombardo, censured by an aging but shrewd godfather, finds himself under pressure to wipe out the incriminating witness or lose face with the administration he has set his sights on ruling.

A psychologist's decision, a judge's ruling, a corrupt police officer, and a sharp-shooting sniper work to stop Cianna from ever entering the courtroom.

But as Cianna walks the white marbled halls of the Chicago Federal Building, Mac senses a rush of victory. Has he failed to remember the pervasive influence of his underworld adversary?