The Man in the Iron Mask – Alexandre Dumas by Alexandre Dumas

"He who has suffered much has the right to demand much."

The Musketeers—Athos, Porthos, and Aramis—are aging, and d'Artagnan is now Captain of the Musketeers. Aramis uncovers a secret: King Louis XIV has a twin brother, Philippe, who has been imprisoned for years, his face hidden behind an iron mask. Aramis plots to replace the King with his twin to rule France, forcing the old friends to choose sides in a deadly game of treason.

The conclusion to the d'Artagnan romances is a tragic and epic tale. It explores themes of loyalty, the burden of kingship, and the end of an era of heroism.