Anti-drugs campaigner Donald Mackay makes deadly enemies with the Griffith mafia and corrupt NSW police. Melbourne crim Ray Chuck plans Australia's most audacious heist - the Great Bookie Robbery.

A naive young Kiwi, Allison Dine, is swept off her feet by Terry Clark, becoming his lover, and most inventive drug courier.

Melbourne standover men Brian and Les Kane have ventured into unfamiliar territory by providing protection for Bob Trimbole's Melbourne heroin dealers. But things turn sour when dealer Wayne Robb is robbed of $200,000 cash on the Kane's turf. The Kane's suspect it was Vinnie Mikkelsen and Laurie Prendergast, two of Ray Chuck's mates from the Great Bookie Robbery.

Terry Clark's drug empire starts to unravel when he is arrested for murder in the UK, while Allison is arrested by the FBI and becomes a star witness against organised crime. With his heroin supplies drying up, Aussie Bob plans Australia's biggest ever cannabis smuggling operation. Meanwhile, the Federal Police have a major win against corruption at the Narcotics Bureau.

The Federal Police prepare to arrest crime boss and cancer sufferer Aussie Bob Trimbole. But a mole within the Feds threatens to create havoc with their investigation. Also, Alison Dine testifies at a coroner's inquest, and blows the lid on the Mr Asia syndicate.