The Melbourne gangland wars start the night the gangster Alphonse Gangitano, "The Black Prince of Lygon Street", and one of the legendary Carlton Crew gang, murders a low-life crim named Greg Workman at a St Kilda party for the sheer hell of it. The charming gangster Alphonse gets away with the murder by convincing two witnesses not to testify but the killing sets the tone for the mayhem that will follow, and sets Alphonse himself on a path to self-destruction.

Convinced that Jason Moran was also involved in the nightclub assault, Steve Owens tricks Jason's driver Carl Williams into revealing that he did indeed ferry Jason to and from the scene. Carl Williams takes the first steps towards building his own empire. The police are determined to crack the "Carlton Crew" crime gang.

Carl Williams is caught red-handed whilst double-crossing the fearsome Moran brothers; the underworld is in an uproar over the mystery source of cheap drugs; a kidnap goes terribly wrong, from farce to disaster, when nobody wants to pay the victim's ransom, which only adds to the tension.

Carl Williams begins his deadly revenge on the crime-controlling Carlton Crew, and tries to increase his ever-expanding grip over the Melbourne crime world; whilst Jason Moran is in jail, his brother Mark takes control of the family business; Detective Steve Owen is determined to prove an underworld murder.

Lewis Moran hires Benji Veniaman to execute his son's, Mark Moran's killer. Subsequently, Veniamen is insulted by the Carton Crew and forms a dangerous alliance with their unpredictable rival Carl Williams; Steve and Jacqui's police instincts are tested when they try to disprove a murderer's alibi; when a criminal is shot dead multiple times, the Police realise there's a monster on the loose.

With their men in jail or dead, the women who love gangsters try to get on with their lives. With Carl Williams in prison, a rival crime boss tries to undermine his empire. A young lawyer falls for her client, a convicted killer linked to the Carlton Crew. The police make a major breakthrough in identifying the mystery hitman they know only as “Benji".

Amid growing public unrest, the police establish Task Force Purana to combat the gangland war. Loan shark Mario Condello faces his own financial crisis, which he solves with brutal efficiency. Bitter rivals Carl Williams and Jason Moran take out contracts on each other’s life. Taskforce Purana detectives are furious when police corruption derails their investigations.

Jason Moran returns from self-imposed exile, determined to destroy his rival Carl Williams; death stalks a children's football match; Taskforce Purana finally gets the resources it needs to defeat the criminals; Benji is under constant police surveillance, so Carl is forced to find a new accomplice; Carl and Roberta celebrate their daughter's christening with a lavish party.

Carl Williams is now the undisputed king of the underworld, confident he can get away with murder; the police make the first major breakthrough in their investigations, but they may be too late to prevent another death; Benji's relationship with Carl and Roberta becomes increasingly personal.

Carl uses his high media profile to accuse Detective Steve Owen of corruption; Graham "Munster" Kinniburgh is gunned down and Mick Gatto tries to convince Carl Williams to end the gangland war; "Benji" Veniamin agrees to kill his former mentor Mick Gatto, but it's Gatto who lives to tell the tale; Carl and Roberta are rocked by the death of their closest friend.

Lewis Caine vows to avenge his best mate Benji's death, but can't trust his new colleagues; lawyer Zarah Garde-Wilson's plans for a romantic future are shattered when her lover is killed; Taskforce Purana finally gets the upper hand in their investigations.

Detective Steve Owen finally gets enough evidence to arrest Carl Williams for murder. After nine years the gangland war is over.