The story follows the experiences of two main characters, a British woman named Ruth Quest and an Australian man named Richard Mahony. Ruth travels to Australia with her husband, who seeks his fortune in the goldfields. However, their relationship becomes strained as they struggle with the challenges of life in the harsh Australian outback."Under the Southern Cross" explores themes of marriage, ambition, and the clash of cultures between British immigrants and Australian settlers. Robins' writing vividly portrays the Australian landscape and the social dynamics of the time, offering insights into the complexities of colonial life.