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 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 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 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 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.

In the series finale, Mary changes the course of history with a decision she makes, and her perilous move for survival causes her to have a stunning realization. Meanwhile, Elizabeth steadies herself for war and becomes the instigator in Mary's demise.

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.

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.

Mary and Darnley wed in a lavish affair, which proves to be a successful decision in regards to her political standing. James makes an interesting discovery about Greer, while Elizabeth frantically tries to salvage England’s power.

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’s life hangs in the balance — Childbirth threatens to take Mary’s life, which leaves her and her unborn child’s safety in jeopardy. Elizabeth discovers that someone in her inner circle was the cause of the death of someone close to her.

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.

When Lord Darnley surprises Mary with a visit in Scotland, Mary sees a glimmer of a union that could be more than just political. Elizabeth fights to gain allies in her favor and Catherine must work to get Claude back on track by finding her a new husband.

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

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.

Mary and Bash 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.

As Mary’s upcoming wedding looms, a terrible tragedy pushes Mary and Darnley apart, forcing Mary to enlist in Catherine’s help. Elizabeth encounters a traitor to Spain, who petitions her to support an expedition to the New World.

Mary realizes she must return to Scotland and raise an army to save her throne; Lola gets caught while trying to help Elizabeth find information about her mother.

Mary's feelings for Gideon are hard to suppress, but she does her best as she seeks political allies. Meanwhile, Elizabeth and Greer face gut-wrenching scenarios; Claude is in danger on her wedding night; and a power struggle over the regency continues.

Mary and Darnley are at odds as their plan to seize England is put into action. Elizabeth is conflicted about her feelings for Gideon. Catherine's son Henri tries to claim the throne from Charles.

Mary teams up with Catherine to deal with Henry, whose deranged behavior puts Francis at risk. Elsewhere, Bash resolves to destroy the Darkness after meeting a boy who survived the horror; and a devoted Lola tries to protect Julien.

Mary's brother visits and asks her to return to Scotland, but Francis is suspicious of his motives. Meanwhile, Penelope takes command as Henry's mental instability progresses; and Lola is skeptical about Julien's marriage proposal.

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.

Mary arrives in France to formalize her arranged marriage to Prince Francis, but complications arise when she meets his attractive half brother and skeptical mother in the series premiere of this historical drama about young monarchs.

Mary takes extreme measures as she tries to stop Francis from catching Condé; a jealous Catherine wants Narcisse to prove himself; Greer makes a decision that could end her relationship with Leith.

As they prepare for a feast, King Antoine tells Francis and Mary about England's plans for revenge.

Francis makes a surprising move after being threatened by King Antoine; Bash and Kenna's marriage is in trouble; Leith makes a discovery about Greer's new career path.

Mary becomes the temporary leader of France; Catherine asks Narcisse for help beating Mary at her own game; Bash sees a familiar face in the village.

Mary aligns herself with France as the threat of England looms; Condé makes an audacious move; Kenna and Gen. Renaude grow closer.

Clarissa kidnaps Henry and Catherine's youngest sons, so Catherine turns to Mary and Bash for help. Elsewhere, Lola tries to assist her brother with a debt, but when she gets in over her head, Francis comes to her aid.

Catherine is suspicious that Mary and Condé are having an affair; Francis becomes ill; Bash's life is in peril; Leith is forced to guard Claude.

Elizabeth must deal with the political backlash of harboring Catherine in England, while Catherine is imprisoned upon her return to France. Mary is forced to make some difficult decisions about securing Scotland's future and Lola is conflicted in her feelings for Narcisse.

Mary and Francis play up their romance after an English envoy expresses doubts about their union. Elsewhere, Catherine seeks to eliminate an individual who's aware of her scheme to destroy Mary.

Mary attempts to help Condé after finding out that the Vatican is after him.

Charles' coronation nears, forcing Mary to find a suitor who will be her ally. Meanwhile, Lola discovers who's been poisoning Elizabeth; and the castle's serial killer has special plans for Catherine.

A matchmaking event is held for the women in the castle, but Lola doesn't want to take part in it. Meanwhile, Kenna grows frightened when Henry flies into another rage, so she turns to Catherine; and Bash learns firsthand about the horrors of the woods.

Tension rises between the Catholics and the Protestants. Francis receives a gift from his dead father. Kenna is shocked by a discovery.

Mary's uncle arrives at the castle and brings dire news about her mother, forcing Mary and Francis to make a tough choice about priorities. Meanwhile, Henry devises a destructive plan; and Bash and Kenna grow closer as they strengthen their forced union.

Some Vatican inquisitors punish those believed to be a Protestant. Lord Condé ends up being abducted.

Queen Mary struggles to hold on to her power in Scotland amidst Queen Elizabeth's campaign to sabotage her with the help of a new ally in Queen Catherine. Meanwhile, with Francis' fate at odds and Elizabeth distracted by temptation in her first love, Robert Dudley, both queens struggle to rule.

As Mary and Francis investigate who was behind the poisoning of King Henry (Alan Van Sprang), they unearth secrets of the past which force Mary to confront her feelings for Conde as she attempts to move forward. Catherine finds herself in the middle of a romantic triangle when the Duke of Guise (guest star Gil Darnell) returns, which forces Narcisse (Craig Parker) to commit a hideous act out of desperation. Meanwhile, Greer (Celina Sinden) finds herself in a situation she never fathomed in order to survive.

An assassination attempt is made on Bash's life, and Catherine appears to be responsible for it. Meanwhile, Mary offers assistance to a jailed peasant who has a curious link to Bash; and Lola tries to stop Catherine from meddling with Bash and Mary.

Mary realizes she must help Catherine in her quest to become regent, even at the risk of hurting the alliance with Scotland. Claude is determined to help Leith marry while Elizabeth struggles with the prospect of losing Dudley.

Claude is forced to marry someone selected by Narcisse. Meanwhile, a surprising discovery is made by Elizabeth, and it could alter her reign; and Mary asks Gideon to help her confirm her suspicions about Prince Don Carlos.

Mary's mother (guest star Amy Brenneman) returns to advise Mary that her throne is in jeopardy. Mary makes a shocking proposition to Conde, along with a bold move to reclaim her throne. Francis moves closer to Lola after a setback with Mary, while King Antoine (guest star Ben Aldridge) makes Kenna an interesting offer. Megan Follows, Craig Parker, Rose Williams, Celina Sinden, Torrance Coombs and Jonathan Keltz also star.

After a tragic earthquake hits Scotland, Mary must face John Knox amidst claims that she isn't coming to the aid of her people. Elizabeth takes drastic measures after she is discovered with Gideon, while Charles makes a decision that backfires.