Joshua Brandon, the co-writer of William Shatner's new autobiography Boldly Go: Reflections on a Life of Awe and Wonder, shares his perspective on the tragic falling out between Shatner and his Star Trek co-star, the late Leonard Nimoy. The 91-year-old actor's new memoir tells many amazing stories from his life and career, with a special emphasis on Shatner's 2021 journey into space aboard Jeff Bezos' Blue Origin spaceship. But one of Shatner's biggest regrets is that Leonard Nimoy passed away during a rift in their friendship.

Leonard Nimoy died on February 27, 2015. In Boldly Go, William Shatner describes how he and Leonard were not on speaking terms for years before Nimoy's death. Bill believes the cause of their falling out was the 2012 filming of his Star Trek documentary, The Captains. Nimoy declined an invitation to participate, and he took issue with being accidentally filmed while Shatner's documentary team was shooting footage at a comic con they both attended as guests. Shatner didn't attend Nimoy's funeral, choosing instead to fulfill a charity obligation. Bill eloquently describes his feelings and regrets about how he never got to reconcile with Leonard in Boldly Go.

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During Screen Rant's interview with Joshua Brandon to promote Boldly Go, we asked his thoughts on William Shatner's falling out with Leonard Nimoy, which they discussed at length while writing the memoir. Here's what Brandon had to say about what happened between the two Star Trek legends:

Screen Rant: I was saddened that Bill and Leonard Nimoy had a falling out. When Leonard died, they never reconciled or patched things up. What's your perspective on what happened between them, based on what Bill has told you?

Joshua Brandon: It is sad because they were friends for 50 years, and they fell out over seemingly nothing... Leonard didn't want to be in his documentary. They were getting B-roll, and the cameras were rolling when Leonard walked on the stage. Leonard was upset about that. Was it something that small or was he pulling away from people as he was getting ill?

But one thing that did make it easier for Bill was that a couple of years later, Julie Nimoy [Leonard's daughter] reached out and said, ‘He loved you. I want you to know that he loved you.’ But it is very sad.

William Shatner Regrets His Falling Out With Leonard Nimoy

Kirk, Spock, and McCoy in Star Trek TMP

As Brandon said, William Shatner and Leonard Nimoy were friends for nearly 50 years, and it's a true tragedy that they had a falling out a few years before Nimoy passed away without a reconciliation. In Boldly Go, Shatner reflects on his efforts to contact Leonard in the years before his death, which went unanswered. Bill also speculated that Leonard may have been pulling away from people because of his illness, and perhaps this is what led to the abrupt end of their friendship in the early 2010s. Shatner goes on to explain that he attended a charity event instead of going to Nimoy's funeral because, as a charity-minded person himself, Bill believed it was what Leonard would have wanted.

Star Trek was built on the eternal friendship between Captain Kirk and Mr. Spock, and William Shatner's own friendship with Leonard Nimoy mirrored it until the end of his life. At least Julie Nimoy provided some solace when she reached out to Shatner to confirm that her father loved him. It's impossible to know for sure why William Shatner and Leonard Nimoy had a falling out so late in their lives, but it's clear that Bill regrets it to this day.

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Boldly Go: Reflections on a Life of Awe and Wonder by William Shatner and Joshua Brandon is available wherever books are sold.