Monsieur Spade centers around the infamous protagonist of American writer Dashiell Hammett's 1930 classic novel The Maltese Falcon. The year is 1963, and the legendary Detective Sam Spade is enjoying his retirement in the South of France. By contrast to his days as a private eye in San Francisco, Spade's life in Bozouls is peaceful and quiet. But the rumored return of his old adversary will change everything. Six beloved nuns have been brutally murdered at the local convent. As the town grieves, secrets emerge, and new leads are established. Spade learns that the murders are somehow connected to a mysterious child who is believed to possess great powers.