Hidden deep in the jungles and mountains of the Southwest Pacific during World War II were Australia's secret army – a group of men and women who reported every movement of the Japanese invaders to Allied intelligence.

The Coastwatcher organisation was formed from a group of volunteers – plantation owners, policemen, missionaries and government officers living in New Guinea and the Solomon Islands. Armed with basic radio technology they were tasked with watching over Australia's porous northern border. They faced not only exhaustion, tropical diseases and malnutrition but were in constant danger of capture and torture by the Japanese military. Their work proved critical to the outcome of World War II.

In this episode Gregory Dobbs chats to Michael Veitch about the state of naval intelligence for the Royal Australian Navy prior to World War II, the impact of the bombing of Pearl Harbour on Australia's intelligence capacity, and the stories of brave men and women who risked their lives by a manning a critical communications network from remote islands in the Pacific.