Mary and Francis are taken hostage when the castle falls under siege, and Catherine makes a shocking suggestion in an effort to save them. Meanwhile, Diane reveals to Bash that she's plotting to have him declared legitimate.

Mary and Francis take drastic action in response to Henry's madness. Meanwhile, a terror in the woods puts everyone in peril; and Mary makes a bold choice when she discovers Lola is in the midst of a life-threatening labor.

Bash and Francis come up with a daring plan whilst Mary has a surprising proposal for Claude.

As Francis thinks Mary is turning against France, she risks everything to take Condé down; Catherine meets with Queen Elizabeth; Kenna's secret will seal the fate of her relationship with Bash.

Grateful for a future with a revived Francis, Mary considers signing away her claim to the English throne, and staying in France forever. Catherine learns that Nostradamus has returned -- with a new vision involving Francis' fate.

When Mary is presumed dead, Elizabeth asks for Lola's help in taking the Scottish crown for herself; James must defend Mary's throne from John Knox; Mary faces Francis's killer.

Mary makes a bold move to defend her reign in Scotland, which results in a battle royale with her cousin, Elizabeth. Lola is accused of a heinous crime and suffers the drastic consequences. Meanwhile, back in France, Catherine finds that Charles has returned a changed man after paying a price for his mother's relentless quest for power.

Mary learns from Lola that she has a chance to get to Scotland safely, but she must act quietly and quickly. When Catherine is framed for murder, Mary must decide if she should stay to protect her, which would jeopardize her safe passage to Scotland.

Mary and Bass return to the castle, where Catherine remains resolved to keep Francis safe from Mary. Meanwhile, Francis learns of the dark prophecy, but it does not dissuade his desire to marry Mary.

Mary uncovers her marriage contract's secret clause, which was added by Catherine and her mother, so she and Francis attempt to persuade the people of Scotland to renounce her mother.

After Mary receives an urgent message from her ailing mother about the dire situation in Scotland, she finds herself looking to Francis for aid. Catherine finds herself up against Narcisse as she fights to become the regent to Charles. Meanwhile, Elizabeth faces continued pressure to wed.

Mary has a chance to get out of her engagement, but it requires lying and sentencing a man to death. Meanwhile, Francis and Bash suspect that Tomas may be disguising his real motives.

Nostradamus shares with Mary his prophecy about a death, which leads Mary to make a big decision concerning Francis. Meanwhile, Clarissa gets brazen as she pursues her goals; and Kenna tells Catherine about Diane's intentions regarding Bash.

Henry claims Catherine has committed treason and adultery, so she attempts to save herself by shedding light on a dark part of Bash's past, and Bash and Mary then try to even the score. Meanwhile, Nostradamus discloses the truth about the castle's ghost.

Mary must decide whether to marry Bash or Francis, who returns accompanied by Lola. Meanwhile, Mary's mother visits and pushes her own agenda, and her mere presence in the castle troubles both Henry and Catherine.

Francis comes to a surprising decision. Mary takes part in a treacherous mission with Lord Condé.

When King Antoine unexpectedly returns to Court, Mary must help Francis hide his weakening condition long enough to secure his family's future. With the Throne in jeopardy and time running out, they must turn to an unlikely ally in need of redemption.

Darnley teams up with John Knox to strip Mary of her throne, which will leave a close friend of Mary's dead. Elizabeth must banish Gideon from court at the request of her future husband, while Charles takes a bold stance against his brother Henri.

A Portuguese prince offers much-needed aid to Scotland if Mary accepts his marriage proposal and break things off with Francis. Elsewhere, Francis' feelings for Mary lead him to put Bash in a risky situation.

Mary's honeymoon ends and she returns to the castle. Meanwhile, Lola displays some odd behavior, which leads to a secret being exposed; Bash finds a bewildered Olivia and asks Nostradamus to assist her; and Henry seeks help from Catherine.

Bash saves Francis' life while they're in the woods exploring the latest ominous threat. Meanwhile, Henry becomes obsessed with a servant who won a contest; Greer is seen kissing a kitchen servant; and Henry forces a new couple into a union.

Mary hires a mercenary to help her save Scotland. Meanwhile, Francis prepares France to wage war on England, and Leith becomes his ally in this endeavor; and Lola and Julien's bond deepens, but she fears he will betray her.

Francis and Mary's new rule is threatened when a plague ravages the land. Kenna's life is at risk. Greer discovers something shocking about Leith.

Mary and Catherine have to hide their identities when they meet a mob of angry peasants. Lola wants to become independent.

Mary must marry again in order to help Scotland, whose welfare she has to prioritize over her heart. Meanwhile, Catherine is accused of poisoning Francis, but Mary believes Catherine is being framed by Narcisse, who's angling to become regent of France.