After a traumatic betrayal forces Jess to seek refuge in the Welsh borders, she becomes haunted by the spectral cries of a child, pulling her into a centuries-old mystery involving a captured Celtic princess. Jess attempts to recover from her personal ordeal, but the discovery of a connection between her current sanctuary and the ancient conflict between King Caratacus and the Roman Empire forces her to confront the past. The narrative alternates between the modern-day investigation and the historical reality of Eigon, the daughter of a king, whose life in Rome holds the key to Jess's own safety. As Jess travels to Italy to uncover the truth, she realizes that the dangers of the past are inextricably linked to the threat still pursuing her in the present.

Readers consistently highlight the author's skill in blending historical detail with contemporary suspense, often noting the immersive quality of the dual-timeline format. The feedback indicates that the atmospheric descriptions of the Welsh landscape and the Roman setting are primary draws for the audience. Many readers appreciate the emotional weight given to the historical figures, particularly the portrayal of the princess Eigon. The consensus among the provided comments is that the book maintains a high level of engagement throughout, with the mystery elements effectively driving the pacing. The author is frequently praised for her ability to maintain a consistent tone across different eras, ensuring that both narrative threads feel equally significant to the overall resolution.