Steven Spielberg and George Lucas‘ creative clash over “Indiana Jones and the Kingdom of the Crystal Skull” was recently revealed in a Spielberg oral history published by Vulture. Franchise producer Kathleen Kennedy noted how Spielberg and leading man Harrison Ford were both “struggling with the movie” because “they didn’t want to do a ‘Raiders’ movie that involved aliens, and they kind of got into a fight with George about it.”

“I wanted it to be kind of a ‘War of the Worlds’ sort of thing,” Lucas remembered. “Harrison said, ‘I’m not going to do another science-fiction movie.’ And Steven said, ‘I’m not going to do another science-fiction movie.’ I said, ‘Steven, this is perfect because it’s the 1950s, when flying saucers were a whole thing,’ but he said ‘no.’ We did about five scripts, and finally Steve and I compromised: ‘Look, what if they’re not aliens but from another dimension.'”

According to Kennedy, Spielberg and Ford “were not 100 percent on board” with the story direction of “Crystal Skull,” which is “why the movie, out of the four that Steven made, is the weakest. And that’s why Harrison was so deeply committed to ‘Dial of Destiny Destiny. He didn’t want [‘Crystal Skyll’] to be the end.”