Tim and John begin their new adventure on Lizard Island, north of Cooktown, taking a look at the health of the Great Barrier Reef.

Tim Flannery and John Doyle travel across the base of the Cape on the second leg of their adventure investigating Australia's northern frontier.

Tim Flannery and John Doyle continue their unique adventure investigating Australia's northern frontier. Ploughing through sodden roads the pair finally make it to Darwin, the big smoke of the north.

John Doyle and Tim Flannery continue their unique adventure investigating Australia's northern frontier, visiting Darwin, capital of the north, and meeting some unwelcome locals.

John Doyle and Tim Flannery continue their unique adventure investigating Australia's northern frontier, finally making their way into the mighty Kimberley.

After two months on the road, John Doyle and Tim Flannery are on the last leg of their journey across the Top End.