'Yellowstone's Kelly Reilly Reveals Full-Circle Moment With '1932's Helen Mirren (Exclusive)

It turns out Mirren is the first professional actor Reilly worked with nearly three decades ago.

Kelly Reilly is so excited about Helen Mirren joining the Yellowstone family she's chomping at the bit to join the cast of 1932. That's impossible, and she admits it. Instead, Reilly will settle for the next best thing -- watching her career come full circle.

Reilly, who plays the booze-chugging firecracker but lovable Beth Dutton, spoke with ET on the red carpet at Paramount's Upfronts at New York City's Carnegie Hall on Tuesday and shared that the news that Mirren and Harrison Ford are headlining 1932 is news that's still hot off the presses.

"I just found out about this yesterday and I wanna be in it, basically, which is impossible," Reilly said. "They're my ancestors. It started with Tim [McGraw] and Faith [Hill] and Isabel [May]."

And now Mirren.

While she won't get the chance to work alongside Mirren on 1932 (working title), Reilly takes solace in that Mirren was the first professional actor she ever worked with. Reilly tells ET she was 16 years old when she appeared on the U.K. drama series Prime Suspect. Reilly joined in season 4 and played the daughter of a lawyer.

"She was incredible and fierce and brilliant and everything I wanted to be as an actor, full of courage and heart," the 44-year-old actress said. "The fact that she is such a big fan of the Yellowstone universe and the writing -- who isn't? It's so juicy. And the fact she is now playing one of Beth Dutton's ancestors, it's a really sweet thing. I'm so excited to see it."

1932the next prequel series in Taylor Sheridan's franchise following 1883, will introduce a new generation of the Dutton family and explore the early 20th century when pandemics, historic drought, the end of Prohibition and the Great Depression all plague the mountain west and the Duttons who call it home.

"She's got such sovereignty and regality and also she can kick it to the dirt as well," said Reilly, continuing her praise for her fellow British actress. "I feel very excited for Taylor Sheridan that he can work with her. It's two giants. And Harrison Ford. These are acting heroes of mine. I will definitely be coming on the set and saying hello."

Mirren and Ford's high-profile castings come three months after the prequel was officially revealed. The series will debut in December on Paramount+.

Reilly also offered some insight into what fans can expect for season 5 of Yellowstone, which kicked off production earlier this week. Season 4 saw Reilly's character finally tie the knot with Rip Wheeler (Cole Hauser) after the family outsmarted a hostile takeover of their rich Yellowstone Ranch. Not to mention they survived a series of coordinated attacks.

"The problem is, how do we top it every year, right?" Reilly asked rhetorically. "Just when I think Beth might be trying to mellow down a little bit -- she's a married woman -- that's not happening. I mean, the married woman part's happening but the calming down. So, it's just, the fierceness is legitimately ramping up."

As for the newlyweds?

"In a strange way, I think Beth is quite old-fashioned in her values," Reilly explained. "I think the fact that this man is now her husband, it holds a lot of power. But he's always been her guy since she was 16 years old. He's the only man -- other than her father -- that she's ever loved. So, the fact that it's official in God's eyes, it's something I think she's incredibly proud of and it probably gives her a little more stability."

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