When a preservationist is killed shortly after seeking help to save a historic building, banker and amateur sleuth Mark Treasure must determine if her death is a tragic accident or a calculated murder. Treasure navigates a web of conflicting interests involving developers, eccentric socialites, and local figures who all stand to gain from the destruction of the 19th-century Round House. As the investigation unfolds, he must reconcile the competing motives of a diverse cast of suspects while uncovering the truth behind the building's architectural significance. The narrative follows a traditional whodunit structure, focusing on the methodical unraveling of alibis and hidden agendas within a coastal resort setting.

This work is characterized by the conventions of the traditional British mystery, emphasizing a puzzle-oriented plot and a sophisticated, observant protagonist. The narrative relies on the interplay between a diverse cast of suspects, each representing different social or economic interests, to drive the mystery forward. The focus on architectural preservation provides a specific, grounded conflict that anchors the investigation in a tangible, real-world debate. Readers of the genre will likely appreciate the methodical approach to the investigation and the witty, lighthearted tone that defines the Mark Treasure series.