A young, female Australian Airforce pilot is involved in a mass brawl between U.S. soldiers on R&R in a Darwin bar in 1945. She is slipped a piece of paper by a U.S. army officer who is murdered shortly before she is helped escape by a tough old tramp steamer skipper. The two are hunted by U.S. soldiers involved in a top-secret project based on an island off Australia’s top end. The two of them are forced to throw themselves on the mercy of the skipper’s long-time rival in the tramp steamer trade, Berty McTavish. Berty is a woman, but as tough as any man. They have to suspend their private war to save themselves and Australia from a betrayal of staggering proportions when a deadly biological weapon is about to be unleashed on an unknowing Australia – by America!