A Milan, sur la Via Monte Napoleone, le braquage d'une bijouterie tourne mal et une petite fille est tuée par un coup de feu tiré par l'un des bandits. Face à l'impuissance de la police locale dirigé par le commissaire Bertone (Raymond Pellegrin), Davide Vannucchi (Henry Silva), le père de la jeune victime, décide d'enquêter lui-même afin de se venger.
Victime de cauchemars et de visions, Franca (Béatrice Romand) est victime d'une sombre machination imaginée par son époux, Antonio (Vittorio Mezzogiorno), dans le but de la guérir. Elle rencontre ainsi un étrange personnage, le professeur (Erland Josephson).
Anna (Marina Suma), une jeune saxophoniste, enquête sur la disparition de sa sœur Elisabetta (Barbara Cupisti), une toxicomane, avec l'aide d'un ami (Richard Hatch). Ils se rendent au Dark Bar, le dernier endroit où Elisabetta a été vue et la retrouve morte. Ils sont pris alors pris en chasse par trois tueurs qui tentent de les éliminer.
David Barrett, the co-owner of a dog-track, discovers that his partner has sold out to gangster Frankie Edare (Stevens) who plans to take sole control of the track and wants to get rid of Barrett. His problems are just beginning, though, as he finds himself involved with Jessica Warren who, unknown to him, was involved in a hit-and-run accident and is trying to set him up for the crime. When Edare kills Barrett's ex-partner to frame him, Barret is falsely accused of committing two murders. Mayhem ensues when the police arrest him, but justice eventually prevails.
Roy Turner (Danton), a mental patient with a violent past, is prematurely released from the ward due to overcrowding. The doctors tell him to avoid stressful situations. Realizing that he can't handle the pressures of big-city life he moves into a beachside motel in a small coastal town. There he falls in love with Susan Mayes (Miller), the daughter of the motel's owner. But when her father discovers that he is a mental patient he threatens Turner to have him recommitted unless he leaves his daughter alone. Turner snaps momentarily, killing him, and he and Suisan flee down the beach. He tries to kill her by pushing her into the water, but comes to his senses and rescues her. He ends up turning himself in.
An old gangster, with a hard drive containing records of who he paid off, is targeted by a competition between dirty cops, internal affairs, etc. The dirty cops hire a thug to get into the safe (in the back of a diner) at midnight. But he brings his friends and goes too early for the time-release lock. Another crooked cop shows up (for uncertain reasons). The shooting ensues and during hostage negotiations the thug tries to put the blame onto an ex-con who just got out of jail, so that no one notices the real target is the hard drive.
Ce film raconte l'histoire réelle de Pietro Nava (Fabrizio Bentivoglio), l'unique témoin oculaire involontaire de l'assassinat par la mafia du magistrat italien Rosario Livatino en 1990. Citoyen ordinaire, Nava décide de ne pas respecter l'omertà, devenant alors une cible prioritaire à abattre car il est susceptible de reconnaître les tueurs et de témoigner contre eux. À l'époque, aucun programme de protection des témoins à risque n'existe en Italie. Nava subit alors les tâtonnements de la justice italienne et bénéficie d'une protection policière permanente qui le force à sacrifier sa vie privée (il quitte sa femme Franca (Margherita Buy) et sa famille, il perd son logement et son métier, doit changer d'identité et se déplacer régulièrement sans pouvoir travailler ni sortir seul et librement) pour continuer à vivre.
Un passionné de cinéma (Robert Sacchi ) se fait refaire le visage pour ressembler à Humphrey Bogart et ouvre un cabinet de détective privé sous le pseudonyme de Sam Marlow.
Catherine Woff (Marjorie Weaver), la fille du riche Dudley Woff (Paul Harvey), est menacée par un homme censé être mort et enterré. Pour démêler cette histoire, Catherine fait appel au détective privé Michael Shayne (Lloyd Nolan).
Michael Shayne (Lloyd Nolan), a private investigator, flees from jury duty to prove the defendant's guilt. He and his girlfriend Judy Taylor (Marjorie Weaver), a reporter, begin looking into the suspect's alibis and discover that in addition to the murder he stands trial for, the man has also killed two others. Afterward, the detective is jailed of 60 days for defecting from the jury.
Inmates pull a prison break, taking the warden and another prisoner as hostages. But when the car gets into a crash, killing the others, the warden makes off with the gang's loot and places the blame on the other hostage.