Kevin Costner on Harrison Ford Joining 'Yellowstone' Universe in '1923' (Exclusive)

Ford and Helen Mirran were announced as the stars for the upcoming prequal.

Kevin Costner is ready for whatever Harrison Ford is bringing to the Yellowstone universe. The actor, who stars as John Dutton in the original series, spoke with ET’s Cassie DiLaura during the Paramount + U.K. launch on Monday, and gave his thoughts about the veteran actor joining Taylor Sheridan's Yellowstone family in the upcoming prequel, 1923. 

“I think people, actors in general, move towards writing,” he says about Ford’s decision to join the cast. “I think that as long as they're going to stay in this game, you want to go to a place that surprises you. If it doesn't surprise you, it's very unlikely that it will surprise an audience.” 

Costner adds, “The truth is you don't want your work to be disposable and you'd like to know if people haven't heard it over here and go, ‘I keep hearing something about it,’ well, you gotta try to make sure that when they see it, there's something special about it. I do know that we've made a fun, compelling series that takes you places and is in an environment, is in a world that is absolutely alive in America.” 

When it comes to offering advice to Ford or Helen Mirren -- who is also set to join the actor in the upcoming series -- Costner says that he’s “not in the advice business.”  

It was announced on Monday that 1923 was the new official title for the series that was originally called 1932, which, according to a press release, was done to account for the end of World War 1 and the start of Prohibition. Per the announcement, both events will be "woven into the story."  

Set 40 years after Sheridan's prior prequel, 1883, 1923 will focus "on the Dutton family’s next two generations as they struggle to survive historic drought, lawlessness and prohibition, and an epidemic of cattle theft; all battled beneath the cloud of Montana’s great depression, which preceded the nation by almost a decade." 

Costner says that he can’t even think about anyone else he would like to see join Sheridan’s Yellowstone universe. “Well, I don't know. I can't even think that way,” he tells ET. “I don't look at this universe I'm in. I'm looking at the next one I’m going to. I just did the very best I can with what I'm doing and then have an idea about the future.” 

In the meantime, Costner is focusing on telling John Dutton’s story -- and is enjoying filming Yellowstone’s fifth season.  

“It’s really good to be out there,” Costner says. “Honestly, it's hard to get tired of those mountains and rivers and horses and things like that.”