Exclusive: Kaley Cuoco and Chris Messina Confront a Serial Killer in ‘Based on a True Story’ (2025)

Actors may bring a bit of themselves to every part they play, but forKaley Cuoco,makingBased on a True Storyrequired an extra dose of real life. When executive producerJason Batemanfirst surfaced the script for Peacock’s comic thriller, the female lead, Ava, was written as a mom raising older kids; Cuoco, now 37, believed that character detail needed to change in order for her to come aboard. A few rewrites later, and she was all in with the updated, childless version of the role.

Then some time went by and life happened—by the time she was preparing to embark on her next big show, Cuoco was expecting her first child with partnerTom Pelphrey. “I went to do some chemistry reads with the producers and some actors, and it was then that I told them, ‘Hey, what do you guys think about if Ava was pregnant?’” Cuoco says. “They looked at me and were like, ‘Oh, my God, are you serious?’ I’m like, ‘Yeah. Sorry!’”

And that leads us to the final version ofBased on a True Story. The first season—all eight episodes premiere June 8 on Peacock—centers on Cuoco’s Ava andChris Messina’s Nathan, a couple residing in West Los Angeles who feel life passing them by. Financial troubles keep tightening with a baby on the way, and their respective careers—Ava’s in real estate, Nathan’s as a tennis coach—seem stalled at best. There’s a missing spark between them too. All of this helps to explain why, following chance encounters with a bartender (Natalia Dyer) and a plumber (Tom Bateman) who are connected to a grisly serial-killer case in their neighborhood, they decide to launch a bizarre podcast that’ll set them up for the uncertain future—and, sure, spice up their humdrum present.

Sound mysterious? It should—especially since the shape of the satirical series shifts wildly from episode to episode. “There’s something about that that’s very frightening and then super exciting, because you’ve got to just jump in and go,” says Messina, a veteran of twisty shows likeDamagesandSharp Objects. “You turn the page every couple weeks and go, Oh, wow, I didn’t expect this.”

Showrunner and creatorCraig Rosenberg(The Boys)first had the idea forBased on a True Storyyears ago, inspired by true crime’s explosion in pop culture. “There’s been podcasts and docudramas and documentaries, murderers becoming celebrities, and celebrities becoming murderers,” he says. “I wanted to write something within that world—how can I really explore some of the more absurd places that this obsession takes people?” After bumping into his old friendMichael Costigan,Bateman’s producing partner under their Aggregate Films banner, Rosenberg pitched the Emmy-winningOzarkalum directly. “Jason’s very good, as you can imagine, with coming up with very specific character-based points of view on material, given his background as an actor,” Rosenberg says.

The tone evolved further with casting; at one point during production, Rosenberg told Cuoco he was surprised by just how funny the takes kept turning out. “They really let me be me,” Cuoco says. “They let me do my Kaley thing.” This is her first series sinceThe Flight Attendant, which earned her Emmy nominations for both producing and acting, and it felt like a natural extension of that work. “I told Craig, ‘I feel like we did a lot of this inFlight Attendant,and I’m very comfortable in the genre,’” she says. “But this felt even stranger and a little quirkier…. All of it just felt like the right fit for me, and it ended up being one of the most enjoyable acting experiences I’ve ever had.”

You can feel it in the performance—an affectionately chaotic take on a woman coming out of her shell. Cuoco began filming while around five months pregnant, and stopped just weeks before giving birth. “It was honestly awesome to write it in because I never had to hide anything,” she says. “I could still eat what I wanted and wear what I wanted, and it worked for the character, which is so rare—that you can keep eating for a role.” Things did get a bit more complicated deeper into production, with body doubles stepping in for “crazy scenes,” including “sex stuff,” and other intensive stunts. “[With my] working nine months pregnant and running around,” Cuoco recalls with a laugh, “four pregnant blondes were walking around at all times.”

Cuoco is an instinctual actor. She doesn’t care much for rehearsal or talking about the next scene; she doesn’t want to watch playback. “She just rolls into it, and she’s just as loose and free and playful,” Messina says of his costar. The two find a sweet dynamic over the course of the season, in part because Messina in no way works that way. “I have 17 acting books in my backpack and an acting coach on speed dial and am just barely getting through it,” he says. “We’re very different…but I just fell in love with her as a friend and a partner.”

As Cuoco puts it, “I feel like I loosened him up a little bit, and he was able to ground me.”

In the pilot, Ava unsuccessfully shows a gorgeous Palisades home to a prospective client. The scene offers a window into her professional crisis, and starkly visualizes the show’s haunting Los Angeles backdrop. This isn’t a show business tale, but it’s still set in “the city of dreams, where reputations matter and appearances matter,” as Rosenberg puts it. The sunshine that constantly bathes our heroes can start to feel punishing, a tease of the spotlight they feel unable—if increasingly determined—to step into.

For Messina, who delivers a nuanced turn as the relatively reluctant Nathan, this particular quality resonated most. “Being an actor, you’re always kind of aware of where you are and where you aren’t, unfortunately—if you just drive down Sunset, you’ll see billboards of stuff that you had no idea was being made,” he says. “There’s a lot of comparisons in this business, which is a little bit of a death to creativity, so I really, really enjoyed playing a guy that felt invisible. I can relate to that.”

Rosenberg, meanwhile, was intrigued by LA’s connection to a specific phenomenon. “If you go back to Jack the Ripper or the Zodiac Killer, they’re not content just to do their horrible crimes—there’s a very strong underlying current of this need to be known and need for fame,” he says. “That also fed into some of the themes that I wanted to explore.”

In the vein of recent true-crime metafictions likeOnly Murders in the BuildingandYou,Based on a True Storycertainly plays around with tropes of the form, before spinning them completely out of bounds. It’s another place where Cuoco felt uniquely at home. “I’m watching 50Datelines every weekend—especially when Tom’s out of town, because it’s not his thing, I’ll watch 20 in a row,” she says. “I am obsessed with true crime. You really can’t believe what people will do.” Well, maybe she’s a little closer now. “I’ve lived in my ownDateline,” she says, “which kind of was my dream in a way!”

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