With the long-awaited release of “Star Wars Episode III: Revenge of the Sith,” the greatest epic series in American cinema comes to a close.

All across America, 40-something-year-old nerds are brushing melted Junior Mints out of the fur of their matted Chewy costumes and hanging them up for good.

And as they do so, they shed long-awaited tears — some of sadness, and some of hopeful joy that George Lucas is going to stop it for a while.

So it’s all over. And where have we as a nation ended up? Well we can all sleep more soundly at night knowing that Luke and Leia, two of the most celebrated and renowned characters in 20th Century American cinema, came from none other than — Natalie Portman?

And I’m sure fans feel more fulfilled knowing a little bit more about the man behind the big helmet. He’s not just a sadistic imperialist bastard. Turns out, Darth Vader is actually a skinny, whiny little boy played rather disrespectfully by Hayden Christensen who phones in his performance with the unskilled boredom of a 16-year-old forced into his high school play by his mom.

Hmm … maybe the mysteries behind these fascinating and mythic characters should have remained just that — a mystery.

Lucas’ obvious intention was to deliver the most emotionally profound episode yet, in which all the mysteries of our favorite characters are unlocked, and all loose ends tied up. But in concluding a 28-year-old epic with images of Hollywood pretty-faces like Portman and Christensen, Lucas falls short of the emotional experience at which he was aiming, and lands awkwardly at a cheap ending swaddled in horrific acting.

As a sci-fi film, it is understood that campy dialogue might take precedence over sharp originality, but as the dialogue slowly collapses during the final 30 minutes, Lucas takes it to a dangerous level of “Highlander 2” proportions.

“Episode III” is not without some redeeming aspects, however. The fortunate participation of Ewan McGregor provides the film with some much needed dignity. McGregor, perfect as always as the young Obi-Wan Kenobi, saves the film from total failure.

But, in all fairness, even aside from McGregor, “Episode III” is reasonably entertaining. Despite a disappointing conclusion that collapsed under a mountain of nauseating performances and dialogue, the final chapter in the greatest American cinematic epic is visually remarkable and relatively exciting.

If nothing else, “Episode III,” despite all its shortcomings, is a sincere effort to pay tribute to an American classic that has survived decades, generations and an eternal war which fans fought valiantly, the Jedi way, with little green plastic light sabers.