By Episode 6, the tension between the Bourbon and Guise families has reached a breaking point. Catherine, ever the survivor, is forced to navigate a court that is increasingly divided by religious friction and personal vendettas.
As Henry lies dying, the power vacuum begins to open. Catherine must pivot instantly from a sidelined queen consort to a woman who must secure her children’s future before her enemies (and Henry’s mistress, Diane de Poitiers) seize control. Why it Matters
This is the "point of no return" for the series. It marks the end of Catherine’s reliance on Henry’s protection and the beginning of her era as the ruthless, calculating "Serpent Queen" who will do anything to maintain the Valois line.