Ron Grey, an ex-Spitfire pilot, embarks on a dubious mission as a courier to gain some quick money, because he only has a few years of active life left - he is a chronic diabetic who daily keeps coma and semi-blindness at bay with insulin shots. While flying a light aircraft with his girlfriend Betty Holmes, the plane strikes trouble and they have to crash land in the Candowie Ranges. When the plane is found by a police search party, they discover that Grey and Holmes have both fled into the bush.