Rahola drew inspiration from historical archives and interviews, including a 2003 interview with the real Bernard Hilda. The book highlights several historical realities of the era:

( L'espia del Ritz in Catalan) is a historical novel published in 2020 by the journalist and author Pilar Rahola. Set in 1942, the book explores the duality of Barcelona during World War II—a city marked by post-Civil War misery and fascist control, yet home to the glamorous and high-stakes environment of the Hotel Ritz. Core Premise and Plot

Shortly after its release, the novel faced a public accusation of plagiarism by the writer . Loperena claimed the book shared significant plot similarities with a manuscript he had submitted to the same publisher years earlier, though Rahola maintained her work was based on independent historical research. L'espia del Ritz - Pilar Rahola | Grup62

The hotel was a critical location where Allied and Axis powers coexisted and spied on one another in a technically neutral Spain.