The kind of classy procedural detective drama that HBO does very well is enhanced all the more by the starring performance of Kate Winslet in “Mare of Easttown” (HBO, 10 p.m.) that premieres tonight.

The English actress becomes a kind of scruffy detective in the Philadelphia outskirts, where she was once the town basketball hero and is now subsumed in all kinds of personal and professional problems, made all the worse by seemingly being related to just about everybody in the town, if not having a long history with them. 

What compelled her to take this jump into such a complicated character (with such a specific regional accent)?

She told an online press session last month, “it was like one of the biggest challenges I think I’ve ever been slapped with.”

“I just had never done anything like this, was excited to read something that just gripped me right away,” Winslet said.  “I really felt the sense of not just who she was, but the world that she lives in, where she comes from, that sense of community, being so entrenched in a society that you sort of forget who you are from time to time, and the sense of responsibility/burdens that Mare carries — for lots of reasons to do with her backstory — really, really intrigued me.  But the story has such a heart to it and it’s rooted in so much truth, and it just really resonated with me.”

But the accent? “Tt drove me crazy,” she said. “Because there are really varying degrees of it… lots of different ways of saying [words]. And the thing that was hardest for me, of course, was to do it well enough that you kind of shouldn’t hear the act of doing it.” 

Jean Smart, Evan Peters, Julianne Nicholson and Guy Pearce are part of the large cast of the seven-part limited series.