Anne-Marie Duff 'Loved the Drama' of Her Character's Surprise Twist in Bad Sisters Season 2: 'Real Cliffhanger, Isn't It?' (Exclusive)

Warning: This post contains spoilers from the first 2 episodes of Bad Sisters season 2.

Anne-Marie Duff was as surprised as anyone by her character's twist in Bad Sisters season 2.

The Irish comedy returned with two episodes after a two-year hiatus on Nov. 13, and saw Duff's Grace Garvey — whose sisters spent season 1 trying to protect from her abusive husband, JP (Claes Bang) — die in a completely shocking fatal car crash.

Duff, 54, tells PEOPLE she wasn't "one hundred percent sure" how Grace was going to go out, but "it wasn't like I was in a soap opera and then suddenly I was like, 'Oh my God!' I didn't have that horrible revelation."

Instead, the British actress says she "loved the drama" of Grace's death — which takes place after a series of mysterious moves by Grace, including her sneaking out of her house while her daughter Blánaid (Saise Quinn) is asleep in the middle of the night.

As Sarah Greene, who plays one of Grace's four sisters, Bibi, tells PEOPLE, Grace's "spiral" right before her death, "and how all the sisters start to doubt [her]" builds the suspense of the crash.

"And the revelation of Roger being involved [in JP's murder]," Greene, 40, continues. "The audience knows that, but the sisters don't know that. And cracks start forming of, Who is this? Who's our sister?"

Duff says Grace's death is supposed to take you by surprise. "It's a real cliffhanger, isn't it?"

She continues, "I sort of relish surprises in drama because I think we can become comfortable, even as viewers watching things. So I love it when somebody suddenly takes a mad turn. It always feeds the monster of the story."

Like Duff, the way Grace died came as a surprise to her costars. "We didn't know how it was going to happen," Greene says. "So yeah, reading it was quite shocking."

"I thought it was done so well, so smart," Eve Hewson, who plays the youngest Garvey sister, Becka, tells PEOPLE. "And also, oh my God, Sharon's performance in that last scene of episode two just killed me."

The only Garvey sister it wasn't a surprise for is Eva, who Sharon Horgan, the creator and executive producer of the show, plays.

Calling it a "bold move," Horgan tells PEOPLE, "I think it was great for the series to have that. We knew it was going to be quite shocking."

"We didn't want five sisters running around trying to sort someone out," she continues. "It felt like the first season was always about protecting Grace, and in a way trying to find out what happened to her, trying to get the answers, and now, [season 2 is about] protecting Blánaid."

Saying goodbye to the cast and the character was emotional for Duff, both because the show "has been such an enormous success" and because "the set for Bad Sisters is an incredibly enjoyable place to be."

"It's very playful, very fun... It really has its own personality," she says — and that's a credit to her costars. "Because they are so extraordinary and sexy and funny, those women — and brilliant at their job — so it can't help but infuse the room."

That energy extends past just the cast, though, as Duff reveals, "The whole crew have a WhatsApp chat. It's amazing. It's the biggest WhatsApp chat anyone's ever belonged to, and everyone's always [active]."

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The first 2 episodes of Bad Sisters season 2 are now streaming on Apple TV+, and new episodes premiere Wednesdays.