Mary (Adelaide Kane) and Darnley (Will Kemp) are at odds as they put their plan to seize England into action. Elizabeth (Rachel Skarsten) is conflicted about her feelings for Gideon (Ben Geurens) as she attempts to find a Catholic to marry. Catherine's (Megan Follows) son Henri (guest star Nick Slater) attempts to claim the throne from Charles (Spencer MacPherson) with the support of Spain and Narcisse (Craig Parker).