Because the story (eventhough it's bad) is fairly complicated, and the transcript is extremely long, here's just a basic plot description:
It's almost Life Day, a Wookiee holiday, and Chewbacca is supposed to go home to his family: his son Lumpy, his wife Mala, and his father Itchy. Han and Chewie try to go to Chewie's home planet Kashyyyk, in the Millennium Falcon, but they run into some trouble with an Imperial Star Destroyer. Han desides to turn back, but Chewie really wants to go to his family. Han agrees, but it may take a lot of time, and they would probably come late.
Meanwhile, the Wookiee family is waiting, and they are all worried. They call their friends Luke and Leia, and ask them if they have seen Chewie, but they haven't. While waiting, the Wookiees watch some stupid forms of entertainment, and Mala tries to cook, and Itchy goes into the fantasy machine. But then, in a scene with Darth Vader, Vader puts an arrest on all planets, and the Wookiee family's house is taken over by a bunch of Stormtroopers and some funny looking Imperials. While the Imperials are there, they also view some stupid forms of entertainment: Lumpy secretly watches the animated segment, the head Imperial listens to some Jefferson Starship, and the Stormtroopers watch 'Life on Tatooine' with Bea Arthur. Near the end, Chewie and Han arrive, and Han makes one of the Stormtroopers fall all the way down the long trees of Kashyyyk. Chewbacca gets the other Stormtroopers to leave, and then Han leaves. But before Han leaves, he calls the Wookiees 'a kind of family'. Then, all the Wookiees in the neighborhood get together for the Lifeday celebration, and to they're surprise, they find Han, Luke, Leia, R2-D2, and C-3PO there. Leia sings a horrible song set to STAR WARS: Main Theme. Then some scenes from Star Wars: A New Hope are shown (about 1 minute) set in chronology, so the whole movie is told in short. Commercials come, and then the credits role, with the original Star Wars end theme.
Michael P. J. Streeter