Duchess Henriette becomes suddenly ill when she returns from a visit to her brother in England. They fear she might have been poisoned, so King Louis XIV shuts all access To Versailles.

With his lover in prison and his wife Henriette surviving a miscarriage Philippe is not a happy man but Louis, buoyant at overcoming his enemies, is keen for an alliance with England for an invasion of the Netherlands and sends Henriette to London to see her brother Charles II and negotiate terms. Cassel and others plot to kill her but the conspiracy is denounced to the king by Montcalm, anxious to be reinstated at court. Fabien survives an attempt to kill him whilst Louis has a job offer for Philippe.

Louis believes to triumph diplomatically when his queen Henriette negotiates an alliance with England against the Dutch for cash and a guard for her brother, English king Charles II, but when William of Orange personally comes question the Stuart 'reunion', Charles offers him a princess's hand. Rohan continues to elude Marchal's efforts to dismantle the secret society in Orange's service, even arranges the escape of a traitor locked up for torture. Marchal, who is losing Louis' confidence, proves the Pau ladies frauds, discretely executes the mother, his 'lover' and the poison monger, and chases the daughter. Chevalier convinces Philippe not to resent Louis' demand to devise elaborate court etiquette but to enjoy becoming the aristocracy at court's puppeteers, while Louis proudly radiates as a heliocentric sun.

The affair of the poisons continues. Could it even reach deep into Louis's own court?

The Queen gave birth to the first royal baby and it triggers some rumors. Besides, Louis XIV's counselors advice him to go to war in order to impose his power. Furthermore, Louis XIV's brother Philippe dreams of glory and wants to be on the field of the future battles.

Philippe returns to Versailles, a super-confident war hero, ready to challenge his brother as the peace treaty with Spain is signed. Louis plans a celebratory party but the attacks on the highway continue and Fabien believes there could be another attempt to kill Louis. Suspicious of Cassel, who refuses to attend the party,as being behind the attacks, the king sends glamorous mistress Athenais de Montespan, accompanied by naive young Sophie de Clermont, to tell Cassel that he must turn up or host it at his own expense. Dangling Sophie as bait Athenais succeeds in forcing Cassel's attendance and obeisance to the king. However the sound of fireworks has a traumatic effect on Philippe, recalling gunfire whilst Sophie shocks her ambitious mother with an unwise liaison and Cassel returns to what is left of his home to find the king has well and truly beaten him.

Louis is struck down with fever and, whilst the official version is that he has had a hunting accident, the courtiers are suspicious and Philippe lets slip to Rohan that, if his brother dies, he will be regent. When the delirious Louis runs round the palace in his night shirt the facts become visible and the queen, Cassel and others meet secretly to plan ahead should he not survive but Louis recovers, thanks to Claudine Masson, daughter of the late court doctor whom Louis now appoints as his physician. Due to Fabien's spy network he also exposes the conspirators, in particular the CHevalier, and orders arrests to be made whilst finally releasing Mademoiselle de Clermont to become a nun on her request.

The King's bed example is blamed for the nobility's immorality, fuelled by illicit love potions and powders. Philippe must meet his new bride. Another victim of poisoning confounds Marchal.

A cool welcome awaits Princess Palatine both in the palace salons and her new husband's bed, but Sophie's destiny is worst. Marchal finds a prime suspect for the poisonings.

Louis ends his relationship with Madame De Montespan who full of humiliation turns to dark forces. Palatine is suffering of suspected poisoning and Cassel reveals Thomas' secret plans to the king.

Louis has Phillipe get close to the spy. This ignites the Chevalier's jealousy. Fabien learns what Father Etienne does with the children he rescues. Montespan is desperate to reclaim the king's love, but Louis falls for someone more pious.

Louis XIV wants the nobility to live at his side in Versailles. But noblemen and noblewomen have to prove their noble origin to obtain this privilege. Montcourt is one of them, but he can't prove his noble rank. Then, Montcourt meets a strange Duke called Cassel to help him. Besides, Louis XIV asks the Queen to welcome Annaba, an African prince.

Cassel's brigands continue to slaughter visitors to Versailles including the king's god-daughter though Fabien has his suspicions as to their identity and arrests a likely suspect, aiming to trap the murderers. Philippe is declared a hero, following his actions at the siege of Cambrai and Louis sends his brother's lover the Chevalier to join him though not before Chevalier has played the king's mistresses against him as several ambitious women arrive at court. Louis visits his brother on the eve of a battle and is taught that, of the two of them, Philippe is clearly the better soldier.

Ex-soldiers working on construction at the palace feel aggrieved at their treatment and down tools. On advice from gardener and confidant Jacques, who suggests a war hero act as intermediary, Louis is nonetheless jealously intransigent when Philippe offers his services. The king's bullying also extends to his refusal to allow ex-mistress Louise de la Valliere to leave for a convent whilst Athenais conducts her own agenda and Cassel, his home burned to the ground, is forced to move into the palace from where he continues to scheme. Louis is ultimately forced to bring Philippe in for a public relations exercise as he breaks the strike, after which Philippe makes his own plans to leave Versailles.

Madeleine de Foix is arrested as the poisoner after trying to kill Fabien. Montespans baby suffers an illness. Louis faces criticism from Bossuet and Pascal. Sophie endures a terrifying experience when married to Cassel.

Louis meets Guillaume d'Orange in a relentless combat and returns to Versailles full of new energy. The court is in shock of two new deaths and Montespan feels herself increasingly isolated.

Though his palace continues to expand and receive admiration from around the world, Louis is still plagued by nightmares.

King Louis XIV's continued insomnia makes him increasingly volatile, meaning Marchal's loyalty counts for nothing. Claudine continues to investigate the mystery toxin, while Sophie seeks a solution to her situation.

A delegation arrives, but won't negotiate with the queen. Phillipe steps up to act as king while Louis is at battle. Fabien mourns Claudine and seeks to avenge her murder. The king's mistress takes her jealousy too far.

In 1667 in France, Louis XIV is a young king who wants to impose his power whereas he is traumatized by the Fronde (the revolt of nobility during Louis XIII's reign) and despite the attacks of conspirators. Then, Louis XIV decides to establish the seat of the power out of Paris, in Versailles. At that time, Versailles is just a hunting lodge but Louis XIV radically wants to transform this castle.

Louis welcomes Leopold, the Emperor vanquished of the Holy Empire, to Versailles. Philip, victorious in the war, was given the task of selecting prisoners to deport them to the colonies. But the presence of a mysterious prisoner with a masked face awakens his suspicions.

Louis and Leopold compete for control of Spain, and Maria Theresa plays a dangerous game by supporting her lover rather than her husband. Philippe continues his investigation on the man with the iron mask. In the salon, the position of Maintenon, the king's pious favorite, is threatened. In Paris, the people refuse to pay taxes.

Louis has Marie-Therese confined to the castle, suspecting her of conspiring against him with Leopold. Louis raises indignation by imprisoning a prominent Protestant philosopher. In Paris, Fabien is released in exchange for prisoners, but Louis asserts his authority by having one of them executed as an example.

Maintenon returns to the palace and encourages Louis to put his plans into action. Louis wants to discredit Leopold, and makes a secret pact with Barek, the Ottoman emissary. Philippe understands that the Church is at the origin of the conspiracy of the man in the iron mask, and suspects Louis to take part. Marie-Thérèse falls seriously ill.

The burning question remains: who is the man with the iron mask? Leto decides to bring the man with the iron mask to Versailles, but Bontemps feels the danger. With the help of Fabien, he removes the prisoner and brings him to Louis and Philippe. The truth is finally revealed.