Carlo and Anna have travelled more than 1500 kilometres across two states, through remote parts of Australia to the capital of Victoria, trying to make sense of why and how the 'ndrangheta spread Down Under. In this final episode, they explore how the role of 'ndrangheta boss has changed in the last decades.

If Carlton and Brunswick are the heart of the 'ndrangheta in Melbourne, the port is where its blood flows. It was here that an infamous drug seizure in 2007 drew attention to the hidden and dangerous world of trafficking. The notorious Tomato Tin bust at the Port of Melbourne was at the time the largest drug bust in the world.

The first official 'ndrangheta murder was in 1945 in Fitzroy and twenty years later the Queen Victoria Market was rocked by a mafia war. But it was on Lygon Street, Carlton's main thoroughfare and the cradle of the Italian community, that the bosses gathered: not only to plot the murder of a rival, but also to eat, socialise, and be seen.

After exploring Griffith and Mildura, Carlo and Anna start the long drive back to Melbourne, 'ndrangheta's "third corner" in Australia. But how exactly is Melbourne connected to the origin of the Honorable Society Down Under? And what is the thread that connects a gruesome murder in post-war Fitzroy to a bloody turf war at the Queen Victoria Market in the 1960s?

Mildura is a beautiful regional town known for food, wine and tourism. But it was here in the 1970s and 80s that the first "mafia tribunals" were established, and it was here that some of the more gruesome murders took place. Carlo and Anna try and untie some of the contradictions of this border town.

In the 1970's the 'ndrangheta was active not just in Griffith, its sphere of influence stretched westward over 300 kilometres to Mildura. And its daily business was more than just violence. But to maintain order in it's ranks violence was often enforced. A tribunal system made key decisions, and held the power to determine life or death.

After a visit to the Coleambally plains - site of the infamous drug busts of the 1970's - it's time to enter Griffith to investigate the disappearance of Donald MacKay. The mysterious fate of the aspiring politician captured the attention of Australia, while the resulting investigation left Griffith in a state of uncertainty that continues to this day.

To understand the rise of the 'ndrangheta in Australia, you can't just stay in the big cities: tracing its origins means hitting the road. Carlo Oreglia and Anna Sergi head up the Hume highway and through the Coleambally plains toward Griffith, the NSW town that was the centre of a national case in the 1970s: the disappearance of aspiring politician Donald Mackay.

According to legend one hundred and two years ago, the Honoured Society made its way from Calabria to Australia. From that moment on, a series of murders, disappearances and spectacular drug busts showed how the 'ndrangheta took hold Down Under over decades. But why, and how did the 'ndrangheta, or Honoured Society, become so prevalent in Australian society? SBS Italian's Carlo Oreglia and mafia expert Dr Anna Sergi hit the road to find out.