Jean Mazarin’s *Monaco, morne plaine* is a French‑language crime novel first issued in 1982. Set against the backdrop of Monaco’s glamorous yet shadowy environment, the story follows a special police unit as it untangles a web of intrigue, corruption, and murder. Mazarin blends procedural detail with atmospheric description, offering readers a glimpse into the high‑stakes world of law enforcement in a locale famed for its wealth and secrecy. The narrative balances tense investigative sequences with character moments, delivering a compact yet engaging entry in the French “spécial‑police” tradition.