Will Bryant and Mary are among the petty common criminals who are condemned by British justice to deportation to the new Botany Bay penal colony in Australia. The long sailing voyage is eventful, with them falling in love but her also seducing the noble, naive lieutenant Ralph Clarke. In the colony, life is terribly harsh. Ultimately, the pair and some other convicts organize a successful escape by boat. Barely alive, they reach Dutch Timor, and hope to be in the clear.