The Oscar winner headlines an emotional new thriller about trouble in a small Delaware town

Mare of EasttownHBO CanadaThe untimely death of a teenager understandably shakes everyone in a close-knit Delaware community to their core, but for troubled police detective Mare Sheehan, played by Oscar-winner Kate Winslet, having to uncover the deep, dark secrets of those close to her stirs emotions the stoic law-enforcement officer has worked hard to repress. When tasked with finding a murderer among her own, Mare is forced to confront past events that have long threatened to tear her apart.

For Winslet, who previously picked up an Emmy for HBO miniseries Mildred Pierce, Mare’s intense struggle to bring justice to her community while, herself, staying above water was a character journey she felt compelled to explore. “The story has such a heart to it, and it’s rooted in so much truth,” says Winslet. “It really resonated with me.”

Mare of EasttownHBO CanadaIn reading Brad Ingelsby’s seven-episode series about how the past can come to define our present, Winslet’s emotions ran the gamut. “It came at a time where I was looking for something that was going to consume me, and it certainly did,” the British actress explains. “Wrapping my head around how I would make this jump from the character I was playing [in period drama Ammonite] to being Mare Sheehan was one of the biggest challenges I’ve ever been slapped with. She’s nothing like me, so that’s pretty scary in a great way if you’re an actor, like me, who likes to feel terrified and exposed.”

Winslet was immediately drawn not just to a character dealing with deep trauma, but the insular world from which she hailed. “I really felt the sense of where she comes from, that sense of community, being so entrenched in a society that you forget who you are from time to time,” says Winslet. “And the sense of responsibility and burdens that Mare carries—for lots of reasons to do with her backstory—really intrigued me.”

If the Titanic actress felt a connection to her character, it was certainly not from a professional standpoint. “I’d be a f***ing lousy detective,” she laughs. “I’d be very good at the coffee and the after-beers, for sure.” But where she could definitely relate to Mare was in the compulsion to fiercely protect her own. “I was able to lean on that real sense of family and how much it means to her to hold that together at all cost,” says Winslet. “Her love for her family is the thing that bolts her down and drives her in life, and that was something that I was able to connect with in the midst of all these other things that were so far-removed from myself.”

Mare of EasttownHBO CanadaAnother trait Winslet shares with Mare is the courage to leap into the unknown—and understanding that the best antidote to fear is putting in the work. “I will say yes to something and then spend the entire time up to shooting it telling myself I can’t play this part,” she says. “My dad has said to me my whole life, ‘You’re only as good as your last gig, babe.’ And I really believe that to this day. The way that I deal with fear is just to honestly face it and do the work.”

To get the hang of the job, Winslet shadowed individuals in the actual Easttown and Marple Township police departments, her goal being not to portray a “TV cop” but pay homage to those who do the real job. “This wonderful woman, [Sergeant Detective] Christine Bleiler, would correct us and I would love it so much,” Winslet explains. “She says, ‘Sometimes it can be messy. It can be a fumble. Things go wrong; allow for that.’ I’d get so obsessed with putting the handcuffs on correctly. She was like, ‘Sometimes one of them falls off and you’re like, oh shoot, I’ve got to do that again on the way to the back of the car.’”

Mare of EasttownHBO CanadaAsk Winslet about her greatest challenge and the answer is unequivocally the highly specific Delaware County (“Delco”) accent, which the actress says drove her “mad” in a way she’d not felt since her Oscar-nominated role in Steve Jobs back in 2015. “What was hardest for me was to do it well enough that you shouldn’t hear the act of doing it. I always hate when you can hear someone doing a voice or doing an accent,” she says. “It was up there amongst the hardest accents I’ve ever done, but it adds so much to the character. I wanted her to really feel as though she had been born and raised there, so I just did the work and kept doing it, and then finally, on the last day of the shoot, I was like, ‘Oh, I think I’ve nailed this now!’ ”

Mare of Easttown airs Sundays at 9 p.m. and 2:10 a.m. on HBO Canada