Ursula Marlowe is not at all a typical aristocrat of the “Belle Epoque” of the early 20th century. She graduated from Oxford University, works as a journalist, participates in the women's rights movement and does not seek to get married. Now Ursula tries herself as an amateur detective and tries solve a series of mysterious murders. Moreover, the victim of one of them was her father, and the main suspect in the other was her best friend. The police see no connection between the crimes. However, Ursula suggests that there is this connection, and perhaps the crimes are related to her father’s mysterious journey to the jungles of South America... To get to the truth, the girl follows this dangerous route.