Jessica's early days were spent in the shadow of Oakland Hall, her family's ancestral home which, owing to financial difficulties, they had been obliged to sell to the rumbustious opal miner, Ben Henniker. Jessica learned that there was a certain mystery surrounding her when she discovered an unconsecrated grave near the house. From the garrulous, irrepressible Ben, she heard the legend of the Green Flash at Sunset, the unique opal reckoned to be the most beautiful in the world, which had disappeared after Ben had shown it to a group of colleagues. Gradually she learned that she was involved in the mystery. Through Ben, she left England for Australia and found herself in the midst of the opal mining community, at the head of which was Joss Madden, a man of power and such pride that he was compared with the peacocks after which Ben had named his Australian mansion. Forced into a marriage distasteful to her, Jessica was caught up in the search for the famous opal which was said to bring ill luck to all those who owned it, yet men committed crimes in order ot possess it. The story is told by Jessica against the dignified background of English country life and the colourful, vital opal mining society of New South Wales. There were the mischievous and not too scrupulous Ben who owned the famous opal; Mrs Laud, the unobtrusive housekeeper who had played a significant part in Ben's life; her quiet son and daughter; the alluring Isa and her complaisant husband; and at the centre of the scene was Joss Madden, the adventurer who, it appeared, would stop at nothing to satisfy his immense pride and love of power. The tension increased with every new discovery until Jessica realized that more was involved than the search for a lost opal and that her own life was threatened.