Bad Sisters: The Cast Breaks Down Their Characters and Motivations to Kill While Viewers Cheer Them On

With Bad Sisters, Sharon Horgan has adapted a Belgian series for Apple TV+ about the five Garvey sisters and the man who tears their world apart and the Garveys' attempts to kill him.

It's not an easy show to watch, as that man, John Paul Williams, who is married to Garvey sister, Grace, is evil incarnate.

Thankfully, the show begins with his funeral, and the central mystery isn't whether or not the sisters trying to kill him were successful but how they pulled it off. Watching the pain he inflicts on the Garveys otherwise would be too much to bear. He's that bad.

On Bad Sisters press day, we had the opportunity to chat with Horgan, who created and stars as Eva Garvey, and costars Sarah Greene (Bibi Garvey), Eva Birthistle (Ursula Flynn), Anne-Marie Duff (Grace Williams), and Claes Bang (John Paul Williams).

When Horgan was offered the opportunity after her former Channel 4 boss moved to Apple TV+ and thought she'd do the production justice. Horgan wasn't so sure, but she watched it anyway.

Horgan said, "I'd never written a thriller or a murder mystery before or adapted or written anything that is hour long. I wasn't in the market for doing any of that, but I watched it.

"I just immediately saw the possibilities and what my version of it would be, and I thought I could make something pretty interesting."

This may be an adapted series, but the adaption is all Sharon Horgan. She kept the original premise but dumped what she called the "bigger and wilder" aspects of the Belgian series (higher body count and the Chinese mafia's involvement, for example).

Horgan explained, "Calming all that down and just making it as much as it could be relatable and to focus more on the actual reality of what it would be when you step over that line and decide to kill someone. You know, are you forever changed? Well, you would be.

"So the collateral damage is not about a body count, it's about the damage it does to the sisters and their relationship and how they move through the world. And so I feel like it's a lot of the big moments we kept and did our versions of, but of everything else sort of changed."

Her costars bring everything to the table as her sisters.

"You have to hold your nerve and trust them because when an actor takes something on, they really do the work. They're not just standing up and saying the lines, they are putting bits of themselves into it and working out their own backstory, and they put the work in. So it's really valuable.

"But there's a little bit of me in all of them and me at various stages of my life. And there's a lot of inspiration from the original series as well. I just had to make them my own."

Writing the youngest Garvey, Becca (Eve Hewson), took Horgan back to her youth in Ireland. "And her kind of wildness was really attractive to write because I thought about myself back then with no strings attached."

While Horgan hasn't had to deal with the death of her parents or the other terrible things the Garvey sisters endure, she understands how they "trade in gallows humor because of that."

More importantly, she says, "They're not strangers to death, so it's quite believable that they could step into it when it comes to it."

With her character, Eva, Horgan sees a lot of herself and other women she knows, natural mothers who have not been able to have children of their own.

"Wanting to [have children but not having them] doesn't make them any less vital. You know, it's a tragic thing, but they aren't tragic women. They're just; their life has gone in a different direction."

Horgan considers Bibi as someone everyone would want to be. "To be that sort of direct and outspoken and to look like that much of a badass must be pretty cool."

John Paul is a terrible man in general, but the Garvey sisters finally act when they realize the toll it's taken on their sister Grace's life.

Greene, who didn't want to give too much away, thinks that Bibi has her own agenda for wanting to destroy (kill) John Paul. "She has her own reasons for wanting him dead, and I think if she didn't get the girls on board, I feel like she would've gone ahead and tried herself anyway.

"Because she has thought about it so much, researched it so much, and I think she's quite a determined person when she's made her mind up that this is what's going to happen. A joy to play," Green said.

Horgan described Ursula as there being "something about her ennui and the feeling that she sort of made mistakes. And she has a lot of sadness in her. "She seems on the outside to be the most sort of accomplished, and the great husband and the three kids and the career and all that. But it's an awful lot of sadness in her."

That's why, when the idea of killing John Paul is on the table, Ursula isn't on board to start. Birthistle said, "Well, I think firstly, she is just so absolutely terrified about how it impacts her life. How is that going to affect her family she doesn't want to go to jail, and she's got kids.

"She goes into straight panic mode of hang on, 'How is this going to affect me?' And she doesn't really think about Grace initially. Then I think when she realizes how bad their initial attempt was going to be because she's coming from a nursing background, she brings a vital skill to the table."

Rather than sitting back and watching her sisters get caught for a botched murder attempt, Ursula decides to get involved. She's not only thinking of her sisters. John Paul has done something that threatens her family, and she's scared of losing them.

Birthistle said, "I think she is involved now in a way that she feels like she probably doesn't have much choice. If she wants to try and stop him in his tracks, it means going in. Again, fairly selfish. Well, we all have our selfish reasons."

As for Ursula's marriage, Birthistle admits it's not great.

"The thing is, she has a lovely husband, Donal, played so beautifully by Jonjo O'Neill. They are really good friends. They got married quite young and for all the right reasons," she said but noted that after the Garveys lost their parents, Ursula might have been too "eager to replace that family unit with her own.

While their marriage worked for a while, Ursula got to the point where it felt like they were just friends, and the world was passing her by. "She wasn't realizing her own full potential. I think she hadn't felt the excitement, and that kind of sexier side of life had been lost many years ago."

How, then, could such strong sisters with their own life issues have missed what was happening with Grace? After years of watching John Paul dominate her, it's hard to understand why they didn't act sooner. Greene says that's simple -- Grace has never asked for help.

"She's constantly defending him. They have a daughter together, and she's covering for him all the time. And also, at that stage, it's so underhanded. There's awful gaslighting going on, and then it's hard to grasp the full extent of that abusive behavior when he does it in such a covert way.

"But I think it just reveals itself more clearly as the story goes on. So, you've got the beautiful yet tragic line about her disappearing, getting smaller and smaller. I think it's when we really feel like, 'Oh, Jesus, we'll lose her altogether.' It comes to a point where it's like, if we don't act now, it will be too late."

All of which brings us to Grace and John Paul and the lovely actors who bring them to life. I can't tell you how much it means that they get along so beautifully. Trust me when I say that any award for most dysfunctional marriage will, in a landslide, be given to Grace and John Paul Williams.

Of course, Bang and Duff agreed with me, which started our interview off on the right foot.

Duff describes Grace as a woman who has almost disappeared after her years of domination.

"She's like a gossamer version of herself. She's inside this desperately difficult, coercive marriage. We know she's lost her way, but she's been so gradually eroded over the years that she doesn't really know who she is anymore outside of being his wife.

"She sees herself as he sees her. So she's constantly trying to adapt and shapeshift and become what she thinks he might need her to be. So it's terribly sad. We don't know who she is really because she doesn't know who she is. She's this woman in deep grief at the start of the show... this little trapped bird. We don't really know who Grace is."

When I told Bang how his portrayal elicited such a ferocious reaction, he laughed, saying, " You make me really laugh ferociously. And I suppose I should be very offended by what you said, but what I really like about what you say is that I suppose it means that we've gotten it right."

"We did the job right. Because I mean, this is very important to the whole show that this is exactly how you feel about him," Bang continued.

"It's very important for you to have sympathy with the sisters in their attempts to kill him all the time and that you want to do the same. That was what was needed from me, I suppose, that I was able to deliver in that department.

"And I mean, Sharon made that very easy because she's written really brilliant scenes and very brilliant dialogue. So it was just, get all your dark sides out and say the lines and don't stumble over the furniture, and then you've got it."

Guff said, "No, but it's the audacity, isn't it? Of what Sharon's written, the audaciousness of him."

John Paul is a character you need to hate, and Horgan's writing makes it effortless to do so.

Guff said, "And it's so shocking. We would get new scenes coming, and we'd all read them, then we were like, 'Oh, I can't believe what he says to her, or her him.'"

Bang cannot imagine anything worse than what's on the page, and it's all there. "The catalog of shit, that's him. I mean, there's nothing really horrendous that he does not do. It is really, really bad, but it's also, and I'm sorry to say this, but it's very much fun."

Bang and Duff got quite a kick out of being in that terrible situation with their characters. They finished each other's sentence to say, "It brings out that joy of playing," without a hint of displeasure at what they were bringing to life.

So many times, actors say that they don't see their characters as evil. They play them as they imagine they see themselves. That's now how Bang approached John Paul.

"No, no, no, no," Bang said. "I mean, of course, as me embodying him, I need to start somewhere else. I can't start by thinking that he's a horrible man. I think I need to sort of find out what drives this.

"And the thing that I think about this one is that he feels that everything is a threat to his family and to himself, and therefore he does all these things, but I can totally see that he is despicable.

"I think it's really important that I, as an actor, also understand that we need that function. We need him to be that because otherwise, it's not going to make any sense that they all want to kill him because that is not allowed. You really need good reasons.

"So I was really trying to give them something to want to kill me over, but I get what you mean. But of course, I can totally see he is terrible. But it's also like there's a perverse joy in sometimes getting to say stuff that you thought, 'I could never say this in real life.' But oh my God, it's so much fun just to say this."

Duff thinks Grace's sisters don't step in sooner because "there is a certain feeling of denial around unhealthy, abusive relationships." But then the show takes viewers into the past so that they realize what they're seeing is just the tipping point to what he's done being unforgivable.

"The virus has spread to such an extent that it is unavoidable. It's undeniable now. Whereas there may have been less of it before. He may have cloaked it in a much more successful way. I think now it's just so out there."

Bang has theories as well, especially when it comes to marriage because even though it's horrible, addressing it will break up your family, however dysfunctional it is.

"I think we go to great lengths sometimes to keep that truth away from us because it's just too much. I mean, the obstacle is just too big, so we will do anything to keep that truth away from us, I think sometimes.

"I think that's what's at the basis of a relationship like this is you're trying to tell yourself things that aren't real. So you gaslight yourself even."

The good news is that you can see all of this excitement for yourself beginning tomorrow on Apple TV+.

Bad Sisters allows viewers to address their deepest, darkest thoughts when they cheer on the Garvey sisters in their attempts to kill John Paul, putting an end to his reign of terror.

Will you be tuning in?

Carissa Pavlica is the managing editor and a staff writer and critic for TV Fanatic. She's a member of the Critic's Choice Association, enjoys mentoring writers, conversing with cats, and passionately discussing the nuances of television and film with anyone who will listen. Follow her on X and email her here at TV Fanatic.