A radical terrorist organization threatens to submerge the Netherlands under the North Sea unless the British government yields to their demands. Detective Lieutenant van Effen, a seasoned investigator with deep ties to the criminal underworld, must infiltrate the FFF terrorist cell to prevent a catastrophic breach of the nation's dyke system. He operates under extreme pressure, navigating a landscape of shifting loyalties and high-stakes espionage. The narrative follows a linear progression, focusing on the tactical maneuvers required to dismantle a sophisticated threat before the clock runs out.

This novel reflects the classic structural hallmarks of the author's later career, prioritizing mechanical tension and procedural detail over character interiority. The premise relies on the specific geographical vulnerabilities of the Netherlands to create a sense of immediate, tangible danger. Readers familiar with the genre will recognize the focus on professional competence and the cold, calculated nature of the antagonist's plot. The narrative maintains a steady, clinical pace that mirrors the methodical approach of the protagonist as he attempts to neutralize the threat.