The attraction of new Star Wars movies is mostly this: A generation of Americans (specifically Gen Xers, but hey, you’re all welcome aboard) gathers together to celebrate one of the cornerstones of global popular culture. I think we can be that bold about the impact of Star Wars as franchise, as brand, as entertainment, as state of mind. And in our sharing we affirm the everlasting validity of both pop culture itself and our own childhoods, while enjoying one last unified cultural experience.

The run-up to what is likely the decade’s most anticipated film has been deliberately low-key. We haven’t been broadsided with trailers and teasers; rather we’ve been teased, so as best to approach the film in a state of spoiler-free wonder. The best tease of all has been the fact that Jedi hero Luke Skywalker has been a virtual no-show in the trailers and behind-the-scenes snippets. Where is he?

I don’t care to know the answer prior to December 17, but I’m enjoying the theatrics. They give me faith that director and co-writer J.J. Abrams understands that the best asset to have in this new movie, and therefore the one deserving the least amount of overexposure, is Mark Hamill’s return to the role of Luke Skywalker.

As movies for a new generation, the sequel trilogy will succeed or fail on the strengths of its new, largely unheralded cast. But the return of the old gang—Luke, Leia, Han, Chewie—will serve up many crowd-cheering moments. It’ll be fun to see Carrie Fisher on the big screen again, smart, sharp of tongue and maybe a Jedi now herself. And though we’ve seen quite enough of Harrison Ford—the one true star of the original cast—over the years, we’ll all be rooting for him to have at least one wily “Han Shoots First” moment.

But the heart of Star Wars, for me, is Luke, and it’s his fate I’m most intrigued by. Will he have a major role or be only a supporting player? Will he, as some have suggested, somehow turn to the dark side? This would be a mistake, of course: Empire and Jedi charted Luke’s various temptations toward the dark side. The culmination of his character arc, his destiny if you will, was not defeating Darth Vader but rather throwing his lightsaber away when facing the Emperor and refusing to turn. To have him succumb or be tempted washes that away.

Maybe he’ll embody the warm-if-weary humanity of his old mentor, Obi-Wan Kenobi. We may get to see him as a veteran Jedi Master, dispensing a villain in a cantina somewhere, or sagely guiding a new generation of Jedi, urging them not to be as reckless as he was. Best of all would be spending time with this beloved character in quiet, reflective moments as he looks back on the events of the old movies and the intervening decades. I mean, if we’re in for nostalgia, let’s do it right.

But as much as I want to see the character, I really want to see the actor. After 1983, Mark Hamill flat-out disappeared. He starred in the three biggest movies ever but never became a star. He vanished into a long and honorable but obscure career of voiceover animation work. (He never even showed up on guest-star factories like The Equalizer or Murder, She Wrote.) I don’t even know what he looks like. Who is he now? What kind of actor is he? What unexpected weight can he bring to the role, having spent 30 years on the dark side of pop culture’s biggest sun?

It matters, I think, because he’s actually quite good in the original movies. When you’re a kid, Han Solo is cool—a rogue, the badass older brother you want to have—and Luke is you. Kind of a dork. But you grow up and you realize that, dramatically, Luke is the far richer character. He’s the emotional center of the original movies, and Hamill makes you believe in Luke at all stages of his journey: mopey teen desperate for adventure, hotshot rebel pilot, game but overmatched Jedi-to-be and mature son trying to save his father’s soul.

I don’t want to oversell Hamill’s talent. He’s not Harrison Ford. But his absence from the movies makes his return to this one so special. New fans will delight at new characters and amazing special effects and John Williams’ legendary score. Older fans will, too, but we know (or should know) that there’s no returning to the innocence of 1977. The original movie came out of nowhere. No chance of that here. No matter how well-kept the new movie’s secrets are, the hype itself has already shaped our expectations. But Mark Hamill remains a mystery, and thus the one presence capable of real surprise.