Warning: This post contains spoilers for Bridgerton season 4, part 1.

Is Bridgerton about to lose one of its staple characters?

In season 4, part 1, Lady Agatha Danbury (Adjoa Andoh) confesses to her longtime friend, Queen Charlotte (Golda Rosheuvel), that she wants to leave London and broaden her horizons after decades spent in high society and among the Queen’s court.

It’s an idea that the Queen does not take well, as she tells her friend she’s not allowed to leave, securing Agatha’s place in London for at least a little while longer, which only estranges the pair further.

Andoh, 63, tells PEOPLE that Agatha’s desire to explore a life outside of London has been a long time coming.

“We meet a woman who we know is very established in this world, but like Charlotte, they’ve come from other worlds,” Andoh says, referring to the backstory fans learned about Agatha’s early life in Queen Charlotte: A Bridgerton Story.

“Even though Danbury came [to London] at 4, well, who was I before 4? What does it look like where I came [from]? I mean, what does she remember of that place?”

“I think we get to moments in our life… where you suddenly want to reflect a bit and think about stuff you maybe haven’t had time to think about — about who you are in the world,” Andoh continues of what her character is thinking this season.

London is “Danbury’s world,” and has been for decades, and Andoh says, “I don’t think she wants to throw away this world, but she needs to set her heart at rest by scratching the itch.”

Given the Queen’s refusal to grant Agatha’s wish, there’s tension between the pair that fans have rarely seen before.

The “juicy conflict,” as Andoh calls it, was “interesting and exciting to play” with Rosheuvel, 55.

“I think lots of us have long friendships, and those friendships do get tested, and how do you sustain them? If you want to hold onto that friendship, what are the compromises that you may have to make in order to sustain it?” Andoh says.

Rosheuvel was equally excited about exploring the new chapter in their characters’ lives. “We’d never seen that before,” she tells PEOPLE of the tension between the Queen and Agatha in season 4.

“We’ve never seen them scream at each other or use these cards in this way. It had always been a kind of equal relationship, an equal friendship, a friendship that was on equal par with each other.”

Andoh adds, “It’s a delight to think, ‘Oh, we’re going to take these characters into that new space. What can we do with that?’ “

Part 1 of Bridgerton season 4 is now streaming on Netflix. Part 2 premieres Feb. 26.