Australia's northward drift slowed down when it collided with Asia about 15 million years ago - in the upheavals, chains of islands were thrust up and eventually they became the stepping stones for an invasion that would change the face of Australia. With the arrival of the first humans - at least 50,000 and possibly as long as 120,000 year ago - a new force entered the continent to shape the fortunes of its plants and animals. The first landfall was on the far north coast of Australia, a rich and tropical region ruled by the annual monsoonal rains. This program tells the story of Australia's top end, where the first Aboriginal people arrived, settled, and perfected the use of fire as a means to manage the landscape.