The Last Musketeer

Fourteen-year-old Greg Rich's family has recently fallen from wealth. After losing their Connecticut estate, Greg's parents moved to a cramped apartment in Queens, and Greg was pulled from his elite private school to a public school where his skills in fencing, horseback riding, and fluent French make him an outcast. When the Louvre contacts the family, offering to buy their antique furniture for its historical value and covering all travel costs, Greg's parents see a lifeline. Greg, however, cannot shake the warnings of his grandfather, Grandpa Gus, who always insisted the heirlooms must never leave the family and must never be taken to France.

In Paris, the family meets Michel Dinicoeur, the Louvre's director of Renaissance acquisitions. While Dinicoeur inspects the furniture, Greg discovers a hidden compartment in his old family desk by twisting a carved fleur-de-lis, a stylized lily emblem, on its back. Inside he finds a diary written by his great-great-grandfather Jacob Rich and secretly pockets it. He also notices that Dinicoeur's right hand is a lifelike prosthetic.

During a private tour, Dinicoeur demands that Greg's mother hand over the black crystal necklace she wears, a cherished heirloom that Grandpa Gus traced back to their ancestor, Cardinal Richelieu, adviser to King Louis XIII. One side of the crystal is jagged, as though half has broken off. When she refuses, Dinicoeur lunges, snaps the chain, and flees. Greg watches him produce a second jagged crystal and fit the two halves together. The resulting flash of light strikes a massive painting of the Louvre's 1615 throne room, which ripples and comes alive. Greg's father tackles Dinicoeur, and both vanish into the canvas. Greg's mother follows, and Greg leaps through after them.

The modern gallery is gone. The room is dark, lit by oil lamps, and the portal winks out behind them. Dinicoeur commands soldiers to arrest the family as assassins of the king. Greg's parents order him to run. He flees through the palace and reaches a window. Outside, modern Paris has vanished: no Eiffel Tower, no skyscrapers, no cars. Only Notre Dame towers above a tiny medieval city. Greg has traveled back in time to 1615.

He escapes into the filthy, walled city and reaches Notre Dame, where a sixteen-year-old cleric named Aramis lives in a garret and secretly carries a rapier. When Captain Valois of the king's guard demands entry, Aramis turns him away, citing the church's legal authority over its own land. Greg tells Aramis a partial truth: A man stole from his family and framed his parents as assassins. Aramis explains that enemies of the crown go to La Mort Triste ("The Sad Death"), a disease-ridden island prison from which few emerge alive. Unable to pronounce "Greg," Aramis nicknames him "D'Artagnan," after a distant French region. Greg recognizes both names as characters from Alexandre Dumas's novel The Three Musketeers, which Dumas claimed were based on real people.

At the city hall, the boys learn that Greg's parents are sentenced to hang in three days. At a nearby marketplace, they witness a teenage soldier named Athos fighting off an entire squad. Greg shouts a warning that saves Athos from a backstab, and all three escape together. Athos, a skilled lower-class soldier falsely accused of mutiny, joins the mission out of gratitude. They then find Porthos, a wealthy teenage nobleman who once survived imprisonment in La Mort. Porthos reveals the prison interior is a pitch-dark labyrinth and that the only map is in Dominic Richelieu's office at the Louvre. Dominic is head of the king's guard and the man who condemned Greg's parents. Porthos volunteers to help.

The four infiltrate the palace by posing as a noble delegation and find the architectural plans in Richelieu's office. During their escape, they encounter Milady de Winter, a sixteen-year-old handmaiden trained to protect the future queen. Greg fabricates a warning about a plot against the queen, and Aramis persuades Milady to lead them to King Louis XIII. Louis turns out to be a lonely fourteen-year-old who has borne the crown since the age of nine. He listens sympathetically but summons Dominic Richelieu for clarification. When Richelieu enters, Greg is stunned: The man is identical to Dinicoeur, only younger, with real flesh-and-blood hands. Richelieu orders their arrest, but the boys escape across scaffolding to their horses.

The boys split up to gather intelligence. Greg and Athos follow Richelieu to a secret nighttime meeting with Milady, while Aramis reports seeing Richelieu at La Mort at the exact same time, proving there are two of him. Aramis also cracks a cipher in Jacob's diary and uses red cabbage water to reveal invisible ink on its blank pages. The hidden text unveils the Rich family's true history: Their original name was Richelieu, and they descend from Dominic himself. Dominic obtained an ancient relic called the Devil's Stone, which, when its two halves were joined, could open portals in time and grant immortality. The original Musketeers exposed his crimes to the king; in the confrontation, D'Artagnan sacrificed his life, and Athos sliced off the band holding the crystal, rendering Dominic powerless. Dominic was imprisoned in the Bastille, a fortified prison in Paris, and the stone was split and dispersed. His son fled to America to found the Rich family with one mandate: Never let the stone return to France. The diary's final warning about confronting Dominic breaks off, the crucial information lost. Greg confesses to Aramis that he is from the future, and they realize Dinicoeur is Dominic himself, centuries older, having traveled back through time to kill the Musketeers before they can ruin his life.

Before dawn, the boys intercept and question Milady, who claims Richelieu coerced her into delivering a sealed letter to a foreign messenger. Greg devises a plan: He tells Milady to report that the boys will attack La Mort at midnight, while they actually strike hours earlier. Greg swims to the island, scales the wall, and detonates the gunpowder stockpile with souvenir matches, blowing the prison doors off their hinges. He navigates the labyrinth using the stolen plans and frees his parents from a subterranean cell. Athos and Porthos row to the island during the chaos. When Dinicoeur emerges with a lit bomb, Athos throws his sword and severs the prosthetic hand holding it. The bomb explodes, blasting Dinicoeur into the river and collapsing part of the prison.

On the north bank, the younger Dominic waits with forty soldiers. He orders them to fire, but King Louis rides out of the darkness with Aramis, who had separately infiltrated the palace and convinced the king to intervene. Louis asserts his sole authority over executions and orders Richelieu arrested. From the nearby woods, Milady watches with satisfaction; the narrative reveals she has been manipulating events to unseat Richelieu and further her own secret plans, viewing the boys as pawns.

One week later, Louis swears in the four boys as his Musketeers, presenting each with a silver sword and tailored uniform. He praises Athos for valor, Porthos for improvisation, Aramis for intelligence, and Greg, "D'Artagnan, the last Musketeer," for his ability to unite others. Greg reflects that he has never felt such belonging, though Dinicoeur escaped into the Seine and was never found, and Greg still needs the Devil's Stone to return home. The ceremony is interrupted by news that Dominic has escaped the Bastille. Greg suspects Dinicoeur is responsible. The boys raise their swords, declare "All for one and one for all," and run for their horses.