Mary & George episode 6 sets up the series finale, and Screen Rant has a clip from the episode. The STARZ series is based on the 2017 book The Kings Assassin: The Fatal Affair of George Villiers and James I by Benjamin Woolley, which in turn is an interpretation of real events that took place in the British royal court in the early 1600s. The show was created by D.C. Moore, whose previous writing credits include Temple and Killing Eve.
https://screenrant.com/mary-and-george-episode-6-julianne-moore-clip/