Based on the available edition record, *Les mystères de l’Allier* is presented as a French-language paperback published by Éditions de Borée. The title points to a regional exploration of unusual stories, local legends, historical curiosities, and unexplained events associated with the Allier department in France. Because the supplied metadata contains no description, subjects, or genres, this summary is necessarily limited to what can be inferred from the title and publication context. The work appears suited to readers interested in French regional history and local heritage, especially material centered on Allier and its communities, landscapes, and traditions. Éditions de Borée is known for regional titles, which supports treating the book as a nonfiction regional history or heritage volume rather than a novel. Additional edition data, such as a table of contents, publisher blurb, or library subject headings, would be needed to confirm the precise scope.