Mark Hamill Recalls Knowing the Big Darth Vader Reveal in 'Star Wars' Before the Cast and Crew

There are few cinematic secrets better than that of Luke Skywalker and Leia Organa's true parentage. According to ComicBook.com, the reveal that Darth Vader is Luke's father was so well hidden that it wasn't actually put into the script at all. Evidently, only three people knew about the moment in advance: Mark Hamill, Star Wars creator George Lucas, and The Empire Strikes Back director Irvin Kershner.

Hamill took to Twitter to explain the pivotal part of the franchise, during which a fake line was used so the real reveal could be dubbed in afterwards, allowing the trio to keep the secret from the cast and crew for over a year. "The cast & crew first learned of it when they saw the finished film," Hamill said to his fans on Twitter. "When we shot it, Vader's line was 'You don't know the truth, Obi-Wan killed your father.' Only Irvin Kershner, George Lucas & I knew what would be dubbed in later. Agony keeping that secret for over a year!"

Props to them for being discreet and not letting the spoiler slip early!

Even with the pressure of keeping such a big plot twist under wraps, Lucas says financial concerns were what plagued him most. “Well, to be very honest, the most challenging aspect was paying for it,” Lucas told StarWars.com (per ComicBook.com) this month. “In order to be able to take control of the movie, I had to pay for it myself. And in order to do that, I did something my father told me never to do, which was to borrow money. But there wasn’t much I could do because I only had maybe half of the money to make the movie so I had to borrow the other half, which put a lot of pressure on me.”

If you feel like reminiscing on a galaxy far, far away, check out this year's May the Fourth celebration compilation here. Star Wars: The Empire Strikes Back, as well as the rest of the Skywalker Saga, is now streaming on Disney+.