Adjoa Andoh says the second half of Bridgerton Season 3 -- premiering Thursday on Netflix -- will see her confident and influential Lady Agatha Danbury lose a bit of her footing.

"We get to see this character, who in the main Bridgerton series, we know is sort of strategic and thoughtful and she has all her ducks in a row. She knows who she is and what she wants," said the Doctor Who and Casualty alum. "We get a further layer of who she is when her past comes back to bite her and that knocks her off her game. It makes her wobble and she has to find a way to strategically deal with it."

Set in 19th century London, the historical romance drama is based on Julia Quinn's bestselling novel series and follows high-society members during their annual matchmaking season.

The first half of Season 3 saw Lady Danbury bristle at the return of her charming brother Lord Marcus (Daniel Francis) and his interest in her widowed friend Violet Bridgerton (Ruth Gemmel), whose son Colin (Luke Newton) has just proposed to Penelope Featherington (Nicola Coughlan), whom he is unaware has been publishing a scandal sheet under the name "Lady Whistledown" for years.

Lord Marcus' Season 3 arrival on the main show reminds her of a part of her personal history she would prefer to forget.

"She doesn't want this person in her life who makes her feel like the vulnerable, powerless young woman that she was," Andoh said.

"She had no power in her marriage, then the marriage finishes, and as a widowed woman in this society, she has absolutely no power, no way to protect her children, and she understands that the only way she's going to get any power is to use her knowledge. We saw that trade she did with Princess Augusta, George's mother in the origin story."

The actress described Lady Danbury's relationship with Marcus as "testy at best," while calling her friendship with Violet in these next few episodes "really complicated."

"We know that Violet knows that Lady Danbury, her dear friend, was romantically entangled with her father [Lord Ledger]. That's complicated enough and now we have the added complication that Agatha fears that her brother may become entangled with her friend," Andoh said.

"She thinks he is of a character that has no moral fortitude or center, and she doesn't want that around her friend," the actress added. "When you have a good friend and they are attracted to somebody that you think is terrible, how do you keep the friendship while actually questioning their wisdom and their emotional sense? It's a tricky one."

Lady Danbury also is trying to entertain Queen Charlotte, who isn't initially impressed with the crop of debutantes presented to her in the beginning of the season.

"So, there's a lot of that going on," she added. "There's some lovely stuff with me and Queen Charlotte in this second half that i'm excited for people to see: the nature of the game, who plays it? how well do they play it? why do they play it."

Lady Danbury adores Penelope, sees herself in this woman and is particularly interested in her romance with Colin, according to Andoh.

"She sees a lot of the overlooked person, the person who's sort of been written off to stay at home and be the spinster, look after Mummy, like she was written off to go and bear children for this man, and never mind if you love him," Andoh said.

"She sees that this woman that hugs the wall and watches everything is a powerful woman and a powerful storyteller, and I think there's something in the untold depth of Penelope that she finds exciting."

Lady Danbury is also fond of Francesca Bridgerton (Hannah Dodd), who ultimately becomes Queen Charlotte's pick as the "diamond" of the season.

"She loved Lord Ledger, so all offspring of Lord Ledger are marvelous to her," Andoh said of her character.

"She wants Francesca to do well, but I think she also quite enjoys the fact that Francesca is doing things her way," she added. "She has the thing that she loves, which is music, and she is very self-possessed and centered in her own unique way."

The first half of the season hinted that Lady Whistledown's true identity might actually be revealed, an event that wouldn't bode well for Colin and Penelope.

"Lady Danbury would be quite interested to go, 'Let's see where the chips fall with this one,'" Andoh said.

"I think if Lady Whistledown was unmasked as a man, Lady Danbury would be pretty pissed off about that. But I think, that aside, there's something fabulous about the power that has been exerted through the pen and through observation and through knowledge, and Lady Danbury loves knowledge," she added. "I think she would be quite interested to see what the vibrations and the reverberations would be for 'the ton' and for Queen Charlotte."

Andoh said she thinks one of the reasons younger people love the show is because the romance and intrigue of balls and posh society events seem so different from the online dating apps so prevalent in the 21st century.

"I was doing a little job today and I was talking to the crew," Andoh said. "They're all saying: 'If you don't use a dating app, there is no other way to meet people. That's what we all do these days.' And my heart sank a little bit for them because that feels really, really tough," she added.

"I suppose you can imagine that those balls are like a physical dating app, in a way, aren't they? You sign your card, and then you see who you end up dancing with and then you move to the next one and the next one."

in a world where so much seems to divide people, Andoh said she finds Bridgerton fans of all ages, nationalities and backgrounds.

"I've just been in Warsaw where we launched the second half of the show and, before that, I was in,South Africa, in Johannesburg, and you know, two completely different continents, and you might think a different sort of demographic, no, everybody loves the show, and everybody comes [to it] with the whole of who they are," she said.

"There is this enormous tent and it's big enough for everybody to come in," she added. "There's something really moving about that. In a world that feels so fractured, that people will just come and be together."