Our Undoing

S3, E8: As Mary (Adelaide Kane) and Catherine (Megan Follows) deal with the aftermath of Prince Don Carlos' (guest star Mark Ghanime) accident, Mary realizes that she will have to marry for the good of her country and not follow her heart. When Catherine is accused of poisoning Francis (Toby Regbo), Lola (Anna Popplewell) is shocked when Mary thinks Narcisse (Craig Parker) framed Catherine in order to become Regent of France. Torrance Coombs, Ben Geurens, Celina Sinden, Rachel Skarsten, Charlie Carrick, Rose Williams and Jonathan Keltz also star.