Ann Pirvu

Mary makes a decision that will change the course of history, forever shaping the fate of her nation, her crown, and her newborn son. Mary's perilous move for her survival causes the stunning realization that perhaps she is not the only one who may not survive. Meanwhile, Elizabeth steadies herself for war and will become the instigator in Mary's demise while later realizing she and Mary might be more similar than either thought.

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 and Darnley are at odds as they put their plan to seize England into action. Elizabeth is conflicted about her feelings for Gideon as she attempts to find a Catholic to marry. Catherine's son Henri (guest star Nick Slater) attempts to claim the throne from Charles with the support of Spain and Narcisse.

As Mary strategizes ways to take over the English throne, Elizabeth struggles to find an appropriate suitor to marry. Meanwhile, James gets caught up in a scheme orchestrated by John Knox and has to deal with the tragic aftermath.

After a tragic earthquake hits Scotland, Mary must face John Knox (Jonathan Goad) 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.