I haven't seen the previous two movies in the Mummy series, although people have recommended them to me as rollicking old-fashioned action-adventure movies, from the same Saturday-afternoon-matinee roots as the Indiana Jones series -- not exactly brain teasers, but good silly fun. The good news is that if you too haven't seen the preceding movies, you can watch The Mummy: Tomb of the Dragon Emperor without fear of getting confused or lost or not understanding the recurring characters. The bad news is that regardless of whether you've watched the other films, the third Mummy entry is a headache-inducing mess that piles on unimpressive special effects to stretch a slight and often incomprehensible storyline.
The movie begins with an extended backstory: the history of the Dragon Emperor from thousands of years ago, in which a ruthless tyrant (Jet Li) bargained with an infamous witch (Michelle Yeoh) in his ambitious drive to seek immortality. The backstory, narrated in a manner befitting the History Channel, goes on for far longer than necessary. (Hellboy II did this so much better and faster, and with cool puppetry too.) It's a full 10 minutes before the story begins and we encounter the leads from the previous Mummy films, Rick O'Connell (Brendan Fraser) and his wife Evelyn (Maria Bello this go-round), who have retired from the action business and are trying to lead humdrum lives in the English countryside.