Detective Inspector Napoleon Bonaparte is summoned to investigate a series of unsettling occurrences at the isolated and ominous Answerth family estate. Tasked with uncovering the truth behind the mansion's reputation for malevolence, Bonaparte must navigate the complex social dynamics of the reclusive family while contending with the treacherous geography of the surrounding lake. The narrative follows his methodical approach to deduction, contrasting his sharp intellect against the atmospheric dread and local superstitions that permeate the island. As he peels back layers of history and family secrets, he faces both physical hazards and the psychological weight of the estate's dark past.

This work is widely regarded as a quintessential example of Arthur Upfield's ability to blend traditional mystery tropes with the unique landscape of the Australian outback. Readers often note the effectiveness of the atmospheric setting, which serves as a character in its own right rather than a mere backdrop. The inclusion of Napoleon Bonaparte provides a consistent, grounding perspective that allows for a deep examination of the cultural tensions present in the narrative. The book is frequently cited for its structural precision and the author's commitment to authentic regional detail, which distinguishes it from contemporary urban crime fiction.