Yellowstone fans debate two wild theories about Spencer Dutton’s 1923 finale ending.

The Yellowstone universe has never been short on drama, but the ending of 1923 Season 1 — particularly Spencer Dutton’s fate — has left fans deep in speculation mode. The final moments, which saw Spencer separated from his wife Alexandra after a tumultuous voyage and left facing an uncertain path back to Montana, were both heartbreaking and infuriating for viewers. Now, two major fan theories are dominating online discussions, and if either one is correct, they could completely change the way Kevin Costner’s Yellowstone plays out.

Theory One: Spencer Never Makes It Back to Montana
Some fans believe that Spencer’s long journey home may never be completed — at least not in the way audiences expect. The 1923 finale leaves him in Europe after being forced off the ship, with Alexandra staying behind under pressure from her aristocratic fiancé and family. If Spencer never reunites with her, it could mean his storyline takes a tragic turn, possibly leading to his death far from home. This theory suggests that the Dutton family’s troubles in Yellowstone stem, in part, from Spencer’s absence in protecting the ranch during the era’s most vulnerable moments. Without him, Jacob Dutton’s leadership might weaken, allowing enemies to tighten their grip on the family legacy. It could also explain certain gaps in the Dutton lineage that Yellowstone has never fully addressed.

Theory Two: Spencer Becomes the Ruthless Protector of the Dutton Legacy
The opposing theory imagines that Spencer does make it back — but he’s forever changed by the hardships of his journey. Fans speculate that the man who returns to Montana will be more hardened, strategic, and merciless than ever before, willing to use extreme measures to defend the ranch. In this version, Spencer’s return could reshape the family’s approach to threats, creating a legacy of aggression and calculated violence that echoes in John Dutton’s methods in Yellowstone. If true, it would imply that much of Kevin Costner’s character’s moral code and no-compromise stance comes directly from Spencer’s example.

What makes these theories so fascinating is that both have the power to ripple through the entire Yellowstone timeline. If Spencer dies or disappears, the family loses a key protector and possibly a crucial branch of the family tree. If he returns and becomes the Duttons’ most fearsome defender, it could explain why future generations — from John Sr. to John III — adopt an unyielding, almost militant approach to protecting their land.

Taylor Sheridan is known for playing the long game in his storytelling, often planting seeds years before they pay off. With 1923 already confirmed for another season, and Yellowstone approaching its final chapters, the question of Spencer’s fate may soon become one of the most important links between the prequel and the flagship show. Whether he’s remembered as the one who never made it home or the man who set the Dutton family’s ruthless tone, Spencer’s story has the potential to alter the emotional and moral core of the Yellowstone universe.

One thing is certain — until Sheridan gives fans their answers, speculation will keep running wild, and every 1923 flashback or reference in Yellowstone will be scrutinized for clues.