Two Jedi knights are sent to a far-off planet to investigate a trade dispute, but their involvement infuriates the evil/powerful Darth Sidious, who sends his highly-trained assassin to eliminate them.
One of the most eagerly awaited and vastly disappointing films of all time, all of which can be laid at George Lucas' feet, mainly his inability to direct actors or write an interesting script with memorable dialogue (note the original trilogy was largely the work of much more talented writers and directors).
Racist stereotypes, unfunny comedy relief (Harold Lloyd was funny; in this context, it's not, and ripping off 75 year old comedies shows a dearth of imagination) and boring talk about trade negotiations make this a joyless experience. The one saving grace is Ewan McGregor, who manages to emulate Alec Guinness without imitating him. At least the next two prequel films were a mild improvement.
For the other films in the STAR WARS series:
Addendum: Lucas has been tweaking his films again for their Blu-Ray release. On the bright side Yoda is much better looking. On the dark side, it shows an incredible insecurity and lack of respect for the people who made the film on Lucas' part. The Star Wars franchise will never become great until Lucas finally takes his hands off the steering wheel or passes on, much as was the case with Gene Roddenberry and Star Trek.