S4, E4: When Lord Darnley (Will Kemp) surprises Mary (Adelaide Kane) with a visit in Scotland, Mary sees a glimmer of a union that could be more than just political. Elizabeth (Rachel Skarsten) fights to gain allies in her favor and Catherine (Megan Follows) must work to get Claude (Rose Williams) back on track by finding her a new husband. Spencer MacPherson, Ben Geurens, Dan Jeannotte, Jonathan Goad, Celina Sinden and Craig Parker star.