Diane Lane’s ‘Feud’ Role Is Inspiring Her to Write a Book Fighting Against ‘Misinformation’: ‘How One Comports Oneself Is Important’

“Is it a gift or is it not a gift that you can only play the age you are?”

It’s a rhetorical question Diane Lane asks — but doesn’t pretend to have the answer to — and also a thought she embraces.

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“I am grateful for it,” she says. “And I’m optimistic that I’m at the right age to play some interesting people.”

Interesting is one of the many things that could be said about Slim Keith. In FX’s “Feud: Capote vs. the Swans,” Lane plays the real-life socialite, who was among the women that acclaimed novelist Truman Capote collected like prized confidantes in the 1960s, before using the secrets they entrusted to him as thinly veiled material for his final unfinished novel, “Answered Prayers.”

A California native, Keith was the pinnacle of elite society and style in the mid-20th century. She was a force in her own right and also the wife of director Howard Hawks, then producer Leland Hayward and finally British banker Kenneth Keith, who held the aristocratic title of Baron Keith of Castleacre.

“Her life was extraordinary,” Lane says. “There really was such a thing as a way to live glamorously, and people just gravitated toward it.”

In the Ryan Murphy series, Truman’s so-called Swans were a group of ladies who lunch, laugh and lord over high society in New York in the 1950s and 1960s. Babe Paley (Naomi Watts) is the bleeding heart of the flock, but Keith is the iron-fisted enforcer who leads the relentless charge to cast Capote out of the gilded world they control, and he covets after his betrayal is revealed. She expects her fellow Swans, including Paley, C.Z. Guest (Chloë Sevigny) and Lee Radziwill (Calista Flockhart) to fall in line — all in the name of friendship, of course.

But as the series nurses the wounds Capote inflicted on the Swans, writer Jon Robin Baitz speculates about the ones they also inflicted on each other. That includes the twist that while Keith was caring for a cancer-stricken Paley, she was also sleeping with her husband, Bill (Treat Williams).

“Is this the right moment to let you know that was sprung on me?” Lane says with a laugh. “We weren’t privy to this turn in the river. They call that the river card in poker, and we had a doozy. It is a tricky thing to talk about because, as an actor, you want to see all the cards in the hand you are expected to play.

“I’m a bit of a skittish horse when it comes to signing on when I don’t get to read what the whole world is going to be. But that is how the game has changed since I have been playing it.”

Not always knowing the ending can be the nature of making television these days, and Lane admits she is still getting used to it even after a busy few years. In addition to “Feud,” she can also currently be seen in Netflix’s “A Man in Full” opposite Jeff Daniels, and she recently appeared in “Extrapolations,” “Y: The Last Man” and even helped to carry “House of Cards” over the finish line.

What swayed her to join “Feud” without knowing the artistic licenses to be taken, though, was the talent on board. She was particularly charmed by Watts’ involvement as Paley and as an executive producer. Add in the other actors, including Demi Moore and Molly Ringwald, and Lane says, “They had me at ‘hello.’”

“This incredible cast of women was kind of a unique experience, really,” she says. “It is rare that you get to work with and spend so much time with such a great group of women because usually you are paired off in some form or fashion. That is just the historic ratio. But I think people are more interested in women’s perspective and experience in the world and are more impacted by women in the world.”

She might not have known where “Feud’s” read on reality would lead, but Lane didn’t go in blind. She devoured Keith’s memoir, “Slim: Memories of a Rich and Imperfect Life,” more than enough times to be able to summon her colorful prose at will.

“You read some of her descriptions of her younger self through the perspective of someone who is at the end of her life and it’s amazing,” Lane says. “The way she portrays herself, very cinematically written, as this young woman in a yellow Packard going into the desert to invent herself from Monterey [Calif.], where she began her life. I just think she was an amazing gal.”

But Lane is reticent to discuss the process of becoming Keith because so much of an actor’s work is interior. Sure, it will grace the screen eventually, but she is very protective of parts that aren’t seen.

For example, in the series’ final episode, which is poetically titled “Phantasm Forgiveness,” Capote spends his final days dreaming up scenarios where he and his Swans make peace — something that never happened. Forcing a confrontation with Slim about his mishandling of their secrets, he pokes and prods at her anger toward him until the pair are throwing jabs and then plates.

While fun in theory, Lane admits the scene was a physical feat of acting that required more than just catharsis.

“Executing things is different than experiencing them,” she says. “I had to achieve a certain thing by throwing those plates, which was quite different than the plate throwing that I’ve had in my personal life. One time was at a Greek restaurant after riding on a donkey outside of Monte Carlo. Don’t ask. It was a Greek tradition, at least according to that restaurant.”

Lane still questions what Capote wanted from Keith in that scene. Had he just asked for forgiveness, it may have been more honest than telling her to let go of her anger.

“But I don’t know that you have to let it go,” Lane wonders. “How about just channeling it? After all, it can be a motivating force for good if you are wise enough to appreciate it.”

While she can’t speak for Keith’s relationship with anger in real life, she is inspired by the socialite’s willingness to lay it all out for the world to interpret before she died in 1990.

“I’m going to write a book myself,” Lane says. “I feel compelled to do it after all this book-writing business and certainly with the internet. At least Slim’s version of her life is there. Yes, she admitted that she omitted a lot, and she learned a lot about the importance of doing that through her experience with Truman. How one comports oneself is important. With the internet, there is so much incorrect information out there, you just want to set the record — from the horse’s mouth, as it were.”

But what will her Slim Keith chapter look like? Lane isn’t sure yet. Though, she can’t help but wonder what Keith would have thought of “Feud.”

“I think she would have liked it perhaps, I’m not sure,” she says. “I wish I could have watched it with her. I wonder if she would have maybe smacked me once or twice for it.

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