There's a pretty classic story about George Lucas and the opening day of "Star Wars" in 1977. As the film premiered in New York and Los Angeles, he was busy in a dark room mixing foreign language versions of the film. His then-wife Marsha arrived and they decided to have dinner together.

Heading toward the Hamburger Hamlet on Hollywood Boulevard, directly across the street from Grauman's Chinese Theater, they sat in a terrible traffic jam, wondering what could be causing such a disruption. It wasn't until they finally reached the restaurant and glanced across the street that they realized what they were seeing. "Star Wars" was playing, and the lines stretched down the block.

"So we sat in Hamburger Hamlet and watched the giant crowd out there, and then I went back and mixed all night," Lucas told author Dale Pollock for his biography of the filmmaker, "Skywalking." "It wasn't excitement, it was amazement."

Imagine the pressure, then, of creating the inevitable sequel to "Star Wars." You have a public clamoring for the latest adventures of Luke, Han and Leia. You have a burgeoning nerd-dom already scooping up collectibles and discussing the film eagerly at conventions and in fanzines. You have pressure from your collaborators and pressure from the studio. Pretty intimidating stuff.

Somehow, Lucas and his team managed to satisfy just about everyone. In 1977, George Lucas transformed Hollywood and popular culture with "Star Wars." But in 1980, he upped the ante by suggesting a new strategy. He defied just about every convention of popular filmmaking, and he let the bad guys win.

By the time the credits roll, "The Empire Strikes Back" has floored you with the emotional impact of a punch in the gut. Five minutes into the film, Luke Skywalker is attacked by a scary snow monster. Two hours later, Han Solo is on his way to Jabba the Hutt, Leia is mourning the loss of her newfound love, and Luke is coming to terms with four words that would change his life forever (not to mention the loss of his right hand).

On the surface, "Empire" is as fun and fast as "Star Wars," and is somehow more relentless than the intense original film. The classic chases between the Millennium Falcon and the Imperial fleet move at a breakneck pace, helped along by John Williams' breathless score. Action moves briskly from an ice planet to a swamp planet to the depths of space and finally to a mystical city in the clouds, where our heroes face the ultimate reckoning against the Empire. Even when the film seems to slow, it never stops.

As Han and Leia and the comic relief wing their way hither and yon in their futile efforts to escape evil, Luke finally learns something of substance about the mysterious Force that flows so strongly through him. His sequences with Yoda provide interludes of humor and depth between the frantic chase sequences, and so it's easy to take them for granted as you wait to soar again through space in the Falcon with Star Destroyers hot on your tail.

Watch Yoda and Luke and Artoo more closely next time you see "Empire"; inhale with your brain and take in every detail. Each scene is a minor gem of magic in filmmaking, especially in today's CG-drenched age, where Frank Oz's puppetry has been pushed aside and replaced by ones and zeroes. You find yourself quickly and fully invested in a puppet and a robot and a young student struggling to grasp profundities rattled off in a grumpy growl. Some have called Lucas' notions about the Force little more than pop hokum; others have adopted them as a near-religion. Whatever your own feelings, there's some beautiful and simple ideas there, expressed by the script and the actors with uncommon grace. "Luminous beings are we, not this crude matter..." We could do a lot worse than to live by those words as we shuffle through this world.

Meanwhile, the Falcon soars on, and the dialogue onboard the spacecraft effortlessly fleshes out the characters through classic one-liners, each of them delivered with the anxiousness of that one panicked moment when all seems lost and they're about to be obliterated by their adversaries. There's not a single scene between Han and Leia that doesn't crackle, as screenwriters Lawrence Kasdan and Leigh Brackett cast Han and Leia as an otherworldly Hepburn and Tracy, quipping their way across the galaxy with the Empire's sinister agents in hot pursuit.

But whatever the fun, whatever the quips, whatever the depth of "Empire," an undercurrent of darkness and desperation runs beneath it all. The desolate opening sequence on Hoth suggests the loneliness and impossibility of the Rebellion's struggle. Throughout, evil is never more than a step behind our heroes. The Falcon never does manage to completely shake the Empire until Han has been frozen in carbonite and Luke has narrowly slipped between Vader's fingers. Even the sequences in which Yoda teaches Luke the ways of the Force are insidiously downbeat--we may learn a lot from the sage Jedi Master, but Luke certainly doesn't seem to.

No moment is more bleak, more impassioned and more desperate than when Artoo finally opens the hatch that will lead Leia and Lando and the rest out to the waiting Falcon at Cloud City. Williams' bittersweet romantic theme for Han and Leia swells, Artoo unleashes a cloud of smoke that provides an uncertain haze, and Leia blasts angrily at the stormtroopers hot on their tail. The look on her face tells us that she has no idea that she'll ever see the man she loves again. It's a crushing moment, and honestly, has a big summer event movie ever managed to crush you emotionally the way "Empire" can? Even when you know that "Return of the Jedi" will come along next and make everything okay, it still has an undeniable impact. It's still a punch in the gut.

The original "Star Wars" trilogy will be available on DVD on September 21, but they'll be the "Special Editions" from 1997, packed with changes that range from the subtle and necessary to the blatant and obnoxious. (Rumor has it that Lucas has made even more changes to the films for their DVD release.) For "Empire" the way it was meant to be seen, you'll need to hit eBay for a laserdisc player and a copy of the last laserdisc boxed set of the trilogy released just before production began on the "Special Editions." I've heard tell you can snag the whole package, player and discs alike, for under $100, but don't quote me on that.

As a sequel, "Empire" did the impossible. It raised every possible stake in the "Star Wars" series. The characters and story gain unexpected new dimensions, and these aspects reflect both backward and forward. That makes "Empire" the heart of the original trilogy.

Taken on its own terms, "The Empire Strikes Back" is as sweeping as "Gone With the Wind," as sharp as "The Philadelphia Story," and perhaps the most simply imaginative sci-fi film ever. The Rebellion may have lost this one, but in the end, it was geeks the world over who won.