A prequel to the best-selling Roma Sub Rosa series traces 18-year-old Gordianus's journey to the Seven Wonders of the World, each of which pose a mystery that challenges his budding powers of deduction and the tenacity of celebrated poet Antipater of Sidon, who fakes his death to accompany young Gordianus.

To rescue an old friend, Gordianus must go behind enemy lines, facing unspeakable danger in the greatest war of the ancient world.

During the Roman Civil War, as the forces of Pompey and Julius Caesar fight a series of battles in the provinces over control of the Republic, Rome itself is a hotbed of intrigue as those left behind wait for word. In this tentative and treacherous environment, a beautiful young seeress is murdered in the marketplace. Possibly mad and claiming no memory of her own past, Cassandra - like her namesake - is reputed to have had the true gift of prophecy...