Duttonheads, the mystery is solved. Yellowstone fans believe that they’ve uncovered the identity of John Dutton’s (Kevin Costner) grandfather. The answer has dogged fans for years, ever since the 1923 prequel series swiftly killed off John Dutton Sr. (James Badge Dale) in season 1, episode 3. His death left a loose thread in the Dutton family tree for over two years. Thanks to a recent event in 1923 season 2, our search may finally come to an end.

First, let’s break down all the information we have so far. In 1923 season 2, the last two surviving family members that could feasibly serve as John Dutton’s grandparents are Spencer Dutton (Brandon Sklenar) and Jack Dutton (Darren Mann). For context: Spencer is James Dutton’s (Tim McGraw) son from 1883, while Jack is John Dutton Sr.’s only son and James’s grandson. (That also makes him Spencer’s nephew.) Both Dutton men also have pregnant wives in season 2.

Everything changes in episode 6. Jack Dutton is shot dead by one of Banner Creighton’s (Jerome Flynn) henchmen, Clyde (Brian Konowal). Though his wife Elizabeth (Michelle Randolph) remains pregnant heading into the finale, an eagle-eyed Yellowstone fan on Reddit recalled that John Dutton once spoke to his grandfather.

In Yellowstone season 4, episode 2, John tells Jimmy (Jefferson White) that his grandfather lost his leg. According to John, his grandfather told him that, “the worst pain he ever felt was in his toes.” Jack can’t exactly live to lose his leg now that he’s dead. So, is Spencer the de facto grandfather? He would need to lose his leg at some point in the future, but it’s still possible!

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Before you head to the comments, I already know what you’re thinking. John could be talking about his maternal grandfather. There’s surprisingly very little that fans know about John’s mother—we don’t even know her name—so I’d say that Yellowstone isn’t too interested in the maternal side of the Dutton family tree. Still, it’s entirely possible that John Dutton’s maternal grandfather lost his leg and not Spencer. Hell, it’s even possible that Taylor Sheridan forgot he ever wrote that line.

Until audiences know for sure following the 1923 season 2 finale, it seems that some fans are already on the right track.

more from the Sheridan-verse:
Exclusive: Meet the Dutton Family’s Worst Nightmare in ‘1923’
Is Luke Grimes Set to Star in a Post-‘Yellowstone’ Spin-off?
The ‘Yellowstone’ Team Is Throwing It Back to ‘1944’