Translated excerpt from the back of the book:
"'Les Ombres de Léningrad & autres Contes' provides three new unpublished in France scenarios for the The Call of Cthulhu (French 6th edition) roleplaying game. Each adventure offers several pregenerated characters, allowing for immediate play. They also contain many game handouts. The keepers can include these stories in their campaign or they can run them independently."
The three scenarios, "Mort à Louxor" (Death in Luxor), "Folie Londonnienne (Madness in Londontown) and "Les Ombres de Léningrad" (Shadows of Leningrad) are all translations of Goodman Games' Age of Cthulhu published adventures, but they have been re-adapted to comply with the Call of Cthulhu system.