Mark Hamill on Luke Skywalker's Dark Return in Star Wars: The Last Jedi: 'I Was Stunned'

Like millions of Star Wars fans, Mark Hamill has been impatient to see Luke Skywalker back in action. In 2015’s Star Wars: The Force Awakens, the famous Jedi made a blink-and-you’ll-miss-it appearance but in Star Wars: The Last Jedi, the character is front and center — just not as you’d expect it.

While Luke takes the spotlight in Episode VIII, Hamill expected to do much more in The Force Awakens, based on early story sketches he saw after signing on to reprise his iconic role. “Luke in scuba gear with Rey, discovering the underwater remains of the destroyed Death Star – there were all these situations,” he says in PEOPLE’s new special issue Star Wars: The Ultimate Guide to The Last Jedi (on newsstands now).

But that story didn’t go the way he thought. “I didn’t know I’d be a literal cliff-hanger, actually standing on a cliff,” Hamill says of Luke’s Force-ful face-off with Rey right before the credits rolled. “In a way, it was a blessing in disguise because I could have all the fun of participation without the pressure of any heavy lifting. It’s different this time.”

The Last Jedi story was a shocker too. “Luke says, ‘It’s time for the Jedi to end.’ This comes from the most optimistic character in the original trilogy,” Hamill says. “I was stunned!”

What led Luke – and Hamill – down such a dark path since 1983’s Return of the Jedi? (“I’m old, bitter and reclusive, just like Luke,” jokes Hamill, 66.) How did Hamill finally embrace his destiny to forever be Luke Skywalker? And what are the stunning secrets of The Last Jedi?

See the clues in the exclusive PeopleTV special and Star Wars: The Ultimate Guide to The Last Jedi.

Star Wars: The Last Jedi hits theaters Dec. 15.