It is the 'Wet Season' in North Queensland. Thirteen year-old navy cadet Andrew Collins and his sister Carmen are in Townsville for the school holidays, staying with their Aunt and Uncle. Walking across the bridge spanning the Ross River, the two siblings rush to the rescue of another boy, Martin, saving him from a beating from three older bullies.

From that moment on, Andrew is plunged into the first great adventure of his life, taking him from one end of Ross River to the other by canoe, bicycle and foot, which brings him to the extremes of both his courage and his physical ability.

He also meets Letitia, a girl quite outside his very limited experience, whose allure will tempt him both morally and emotionally.