‘Magpie Murders’ gives Lesley Manville the stretch she seeks

“What gets me up in the morning is that I can play Susan Ryeland and then I can play Princess Margaret and then I can play Ada Harris and they’re all different ends of the social spectrum,” she says. “I get excited when it’s a character or type of character that I’ve not really played before.”

That’s Ryeland, a book editor, who investigates the death of a writer and the missing chapters in his latest novel. She’s the centerpiece of “Masterpiece’s” latest offering, “Magpie Murders.”

Because the character doesn’t arrive until nearly halfway through the book, author Anthony Horowitz had to do some adjusting for the television adaptation.

“If you have a talent such as Lesley, you do not leave her until Episode 4,” Horowitz says. Rather than set it in two time zones, two worlds and two eras (as the book did), he starts with Ryeland and works through Atticus Pund, the character the writer created, to solve the crime.

“The key person is Atticus and, in a way, (the two) become one mind. She’s not a detective but she’s got these detective antennae on the go,” Manville says.

Tim McMullan, who plays Pund, says the character has “fantastic interest in people…and he believes there’s no such thing as coincidence, so every little thing is on the scale. He discovers who commits the crime almost with as much sorrow as triumph because we’re all in this together.”

What Manville loved about Ryeland is her independence. “She doesn’t have to explain herself,” she says. “She’s chosen not to get married. She’s chosen not to have children….and she still drives an open-top sports car. She’s absolutely not conforming to anything. It was just wonderful playing the scenes when she just kind of cuts these men off absolutely brilliantly with her language and her skills.

“I’m so glad Anthony didn’t write her as sort of a 20-, 30-year-old something. It’s just so great that she’s got all this gravitas and experience. We need to see more women on film that are represented in that way. You can still be quite exciting, even though you’re over 50, oddly enough.”

Earlier this year, the 66-year-old Manville played a much more submissive woman, Ada Harris, in “Mrs. Harris Goes to Paris.” Currently, she’s portraying Princess Margaret in the final two seasons of “The Crown.”

For her work as the crisp sister of a dressmaker in “Phantom Thread,” she was nominated for an Academy Award. She followed that with “Let Him Go,” a western in which she played the mother to an unhinged group of cowboys.

“Magpie Murders,” she says, heightened her own sleuthing skills. “If I wasn’t an actress, I’d be a detective because I would make a brilliant one. I’ve had ex-boyfriends who still don’t know how I found out stuff about them and, honestly, they’ll never know.”

“Magpie Murders” airs Oct. 16-Nov. 20 on PBS’ “Masterpiece.”