The rogue who would later call himself Eugène François Vidocq is born in a prison cell, the twelfth child of a mother who steals a loaf of bread each time she needs shelter to give birth. As he grows, he drifts in and out of jail, his life a threadbare pattern of lawbreaking and narrow escapes. At the story’s start, he and his cutpurse partner, Emile Vernet, slip away using a file hidden inside a birthday cake gifted by Vernet’s aunt Aunt Ernestine.
On their way toward Paris, the two are hired to pose for a painter: Vidocq in the role of Saint George and Vernet as the dragon. As the church painting nears completion, they even steal the horse Vidocq is posing with. In Paris, Uncle Hugo, the head of Vernet’s criminal clan, considers the safest route for the fugitives to be in the army. A forger among Vernet’s kin equips Vidocq with a falsified commission as Lieutenant “Rousseau,” and the plan turns toward military service rather than endless running.
In Marseille, while awaiting shipment to Napoleon’s campaign in Egypt, Vidocq meets a singer named Loretta, who is drawn to him, even as he is drawn to her ruby garter. He accompanies her to meet her dull admirer, Prefect Richet, but ends up stealing Loretta’s garter instead and letting curiosity steer his choices.
Two years pass, and Vidocq and Vernet return to Paris, taking a detour past the church that bears their own likenesses. There they encounter the jewel‑laden Marquise De Pierremont, who invites Vidocq to her chateau after he retrieves her pet monkey from a cemetery, even claiming a distant relation to a Vidocq buried there. He is both wary of and captivated by Therese, the Marquise’s daughter, while learning that her future husband is the powerful Minister of Police she already knows as Richet. Therese, nothing short of intrigued by the image of Saint George, feels a kinship with Vidocq and begins to tilt toward a life of crime alongside him. Vidocq and Vernet steal the Marquise’s jewels, intending to return for them later.
But the Minister’s authority shifts when he fires Richet, who becomes the police chief under the new regime. Vidocq’s plan is reshaped by a grander scheme: through “deduction,” he leads the minister to the hidden jewels and, in the process, secures Richet’s old position. He also places Vernet’s entire clan into the Bank of Paris workforce, arranging a bold theft from that institution.
Trouble arrives when Loretta reappears in Vidocq’s life and reveals that she has married Richet. She uses this new tie to blackmail Vidocq into resuming their relationship, while the stakeout for the bank robbery proceeds. Vidocq walks with Therese and her younger sister Mimi De Pierremont, and Therese confides that she has deduced Vidocq’s jewel thefts but is still willing to follow him.
A jealous Richet bursts into Loretta’s hat shop, threatening to end her life and then, in a fury, shoots Loretta. With that obstacle removed, Vidocq tells Vernet’s family that he has changed his mind about the crime, but Vernet ambushes him, leading to a deadly confrontation in which Vidocq is forced to kill Vernet.
In the aftermath, Vidocq confesses his past crimes to the minister and the Marquise. Having truly repented, he is forgiven by the De Pierremonts and welcomed into the family as he marries Therese, sealing a transformation from lifelong fugitive to a reformed figure in their ranks.
