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.

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 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 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.

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

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

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.