When a scientist vanishes following the suspicious suicide of his colleague, an investigator follows a trail of secrets that leads to a remote island. Richard Hendon initiates an inquiry into the disappearance of Paul Clyro, a researcher previously engaged in classified viral studies. The narrative follows Hendon as he navigates the social and professional circles surrounding the deceased colleague, Wolsingham, eventually tracking the trail to Madeira. The story operates within the conventions of the classic British mystery, emphasizing logical deduction and the uncovering of hidden motives behind a facade of normalcy. The narrative framework maintains a steady, methodical pace as the protagonist confronts the physical and psychological distance between the initial crime scene and the eventual discovery of Gavin Chilmark.

Readers frequently highlight the author's ability to construct intricate puzzles within seemingly mundane social settings. Discussion often centers on the clinical precision of the investigation and the slow-burn tension that characterizes the protagonist's search. Critics note that the pacing favors character-driven dialogue over high-octane action, which aligns with the traditional mystery genre expectations. The effectiveness of the atmospheric shift to the island of Madeira is often cited as a key element in the book's success. Readers appreciate the logical consistency of the plot and the author's skill in maintaining suspense without relying on excessive violence.