Enigma is set in 1960 in an hypothetical university department in Adelaide, where two imaginary students are studying for PhDs. It is loosely based on Pat Stevenson's life experiences. Judith, indigenous and impecunious, and Arthur, son of a wealthy station owner, are thrown together in a cell science laboratory where they work together on related research topics. Although Judith and Arthur have equal status within the university, their extra-curricular lives represent two ends of the social spectrum. Their only meeting point is music.The immigrant population of Adelaide (New Australians) play an important part in the story. They are more welcome in White Australia than Judith who is not accepted as an Australian citizen in 1960.The theme of the book is discrimination in academia between rich and poor; race and gender; yet united by science as an international endeavour. It is a true historical record of scientific method before computers, photocopiers, detergents and throwaway equipment. While the most important attribute of a scientist is honesty, achievement is dependent on luck and determination.' (Publication summary)