The first family of country music had recurring roles in the '90s on CBS' Dr. Quinn, Medicine Woman. Johnny Cash plays the grizzled gunslinger Kid Cole in four episodes, while June Carter Cash made three appearances as the spiritual healer Sister Ruth.
The guest stars' screen time was limited, considering the show lasted six seasons and 149 episodes, yet their presence made an impact on Dr. Michaela Quinn herself: future Carter Cash confidant Jane Seymour. In turn, Seymour would play a major yet uncredited role in the creation of the 2005 film Walk the Line.
"One of the great moments in my life was when Johnny Cash and June Carter Cash, his wife, came to work on Dr. Quinn, Medicine Woman," Seymour said in a 2018 Facebook video. "I mean, it was just one of the most exciting things ever. The entire crew and all the cast were just, 'Oh my gosh, Johnny Cash is really going to be here!'"
Seymour bonded with June, who was born in a county neighboring the TV series' Virginia setting, over their comparable senses of humor.
"She used to get me in giggles," Seymour recalled. "We got in the worst trouble on Dr. Quinn. We couldn't even look at each other."
Johnny took a liking to Seymour's then-husband James Keach, partly because of the Hollywood veteran and his brother Stacy's roles in Cash family favorite The Long Riders.
The couples became such fast friends that the Man in Black was the namesake and godfather of one of Seymour and Keach's twin sons, Johnny Keach.
As the Keach-Seymour and Carter-Cash clans became closer and started hanging out together near Nashville, seeds were planted for a big-screen love story that could rival that of Dr. Mike and Byron Sully (played by series co-star Joe Lando).
"Johnny turned to us and said, 'Someone is going to make the story of my life,'" Seymour said (as quoted by SWVA Today). "He said, 'I don't really have anyone that I can trust.'"
Keach and Seymour conducted a series of interviews with Johnny and June in the '90s that informed Gill Dennis' original script of what became Walk the Line.
"Between James and Johnny, there was such a deep connection that James got John to open up about a lot of stuff -- a lot of very dark, tough stuff for him to deal with," Seymour told the Pittsburg Post-Gazette. "He managed to help John realize that if he was going to tell the story, he couldn't just tell the glossed-over version. He had to tell the gnarly truth."
James Mangold and his wife, producer Cathy Konrad, would later develop the script that'd ultimately become an Oscar-winning biopic for Fox 2000.
While Seymour's contributions went uncredited, Keach got to appear in the film as a Folsom Prison warden.
"The coolest thing about playing the warden for me is, off-screen, you hear 'Mr. Cash' -- the first time you hear his name, it's me," Keach told the Pittsburg Post-Gazette. "I'm the first guy who says his name, and I was the one who started the movie."