Set in 1901, the film follows the progress of Constable Peterson (Matthaei) on his quest to bring an Aboriginal man (Kamahl) to justice under the White Man's law. Having heard of a killing that took place under tribal law, Peterson embarks on a mission to arrest the accused man with the help of Black Tracker Jubbal (Devereaux) and bring him back to Melbourne for trial. It is a journey of discovery for both Peterson and Jubbal. Jubbal finds himself caught between black and white society, eventually dying following a curse placed on him during a traditional bone pointing ceremony. Peterson is left to try take the prisoner back to Melbourne alone, but cannot negotiate the pitfalls of the desert without the help of his prisoner. During the latter stages of his return, Peterson begins to understand the folly of his mission, releasing the Aboriginal man to return to his people. Finally, the metaphorical journey out of darkness is the one made by Peterson.

An evil scientist, Parta Beno, who has been found guilty of imprisoning and reducing in size inhabitants of various planets. As punishment he is exiled to a remote asteroid, with the only amenities being a crude laboratory. All the specimens that Parta Beno collected were sent back to their home worlds by the World Council, except those few that the Council had no knowledge of, let alone any idea about the planets from whence they came. The hand-picked crew of 'The Interpretaris' were given the mission of returning these aliens to their home planets.