Directed by Lucas' old film school professor Irvin Kershner TESB is emotionally rounded, thematically rich, funny, compelling and imaginative. It doesn't pander to pre-teens as the disastrous "Return of the Jedi" would, doesn't have the kind of slapped-together-for-a-buck-three-eighty look that plagued parts of the original film and - perhaps as important as the fact that it was helmed by an actual film director - it's cast was first rate and had developed a kind of easy rapport with one another that gave the whole enterprise a sense of relaxed believability.
Picking up three years after the events of the first film TESB opens with the rebels in retreat and hiding out on the ice planet of Hoth. On a patrol mission Luke decides to check out an apparent meteorite strike and is attacked by a snow monster and dragged to its cave to await ingestion. When he fails to return to base his friends become alarmed and we're treated to some real character development. Leia and Han are interrupted during a touching and remarkably satisfying scene in which their true feelings for each other finally come to the fore. Han promptly takes control of events and heads out into the dark to find his friend. It's the kind of well modulated emotional sequence that is completely missing from later installments.
Han does of course find and rescue Luke and the story moves onward and outward from there as all the main characters escape the onslaught of the Empire that has tracked them down to Hoth on one of Darth Vader's hunches. Luke, though, is driven by a vision to go to the the Dagobah system where an apparition of Obi Wan told him he'll be instructed in the ways of the force by Yoda, the ultimate Jedi master. There among the fetid, claustrophobic, dimly lit swamps the story ascends into something approaching true myth as Luke is forced to examine his motivations and their possible consequences. It's also there that we're introduced to Yoda in the form of a puppet brought to life by the voice of Frank Oz and the wizardry of the puppeteers. Even after the story leaves Dagobah the emotional resonance remains and informs the remainder of the movie.
Luke returns to try and rescue his friends who've been double-crossed by Han's old buddy Lando Calrissian (Billy Dee Williams) and delivered to Vader lock, stock and barrel in return for Vader's promise to leave Calrissian's Cloud City alone. Vader of course has no intention of letting Cloud City retain something like autonomy and this inspires Lando (ever the opportunist) to switch sides again and aid Luke in his rescue attempt. That attempt, though mostly successful, fails to do much for Han who had been frozen in carbonite and turned over to Boba Fet before Luke arrived.
After Leia and company escape Luke stays behind to confront Vader and in their climactic battle over the gaping yaw of Cloud City's core Vader makes one of the most famous proclamations in movie history.
But it's not the plot details of The Empire Strikes Back that make it so compelling a film. It's the little things. The fact that Lucas and Kirshner don't allow the story to be overwhelmed by special effects. The believeability of the interactions between all the main characters, the willingness to allow the narrative to explore the dark side of the hero myth and Kirshner's patient character development. The quiet scenes carry every bit as much punch as any of the action scenes. For example the reaction of R2D2 and Yoda to Luke's decision to confront what awaits him in the forest on Dagobah. The scene early on where C3P0, R2, Leia and Chewbacca have to deal with the possibility that Han has just sealed his own fate by going out alone to look for Luke at nightfall on Hoth. Vader's stunned silence as Luke falls away from him.
These are all the telltale signs of a master film maker at work and one can only rue the fact that Kirshner was not in the director's chair for the third film. But by then Lucas had made his decision to use Star Wars as nothing more than a marketing platform for toys and video games and storytelling was no longer required.
Still, we have The Empire Strikes Back to enjoy. A great film that in its conceptual completeness, subtlety and emotional depth stands shoulder to shoulder with the best sci-fi movies ever made.