The French novelist Alexandre Dumas had some African blood, for which he was sometimes vilified; despite his immense popularity in the mid-19th century, hostile critics could publish, “Scratch Monsieur Dumas’ hide and you will find the savage . . . a Negro!” In “The Black Count,” Tom Reiss traces the novelist’s African origins through the story of his father, aspiring to make this biography as riveting as Dumas’s most successful works, like “The Three Musketeers” and “The Count of Monte Cristo.”

The raw material is extremely promising for a thrilling historical epic, sweeping through the French Revolution at home and abroad, and the Napoleonic Empire that followed. The novelist’s French grandfather, Alexandre Antoine Davy de la Pailleterie, was a minor French nobleman who emigrated to French Saint Domingue (today’s Haiti), where his younger brother was a wealthy sugar planter. The brothers soon quarreled, and Antoine absconded with a handful of slaves from the plantation and disappeared into the colony’s impenetrable mountains. He had four children with a black or mixed-blood woman known as Marie Cessette Dumas, and shortly before his return to France in 1775 he sold the mother and three of the children as slaves. The fourth son, Thomas-Alexandre Dumas Davy de la Pailletrie, was also sold, but “conditionally, with the right of redemption.”