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 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.

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.

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.

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.

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.

A powerful and dominating Lord learns Mary was responsible for his son's death, he demands retribution. Francis and Lola return to the castle with their new son.

Shadowy riders have attacked a shepherd, Lord Conde and Bash investigate. Mary reconsiders her relationship with Lola. Leith returns to court.