Brendan Fraser, with his boyish face and trademark hair flop, hasn't exactly entered the Harrison Ford grumpy-old-man zone, so it's discombobulating to learn that in The Mummy: Tomb of the Dragon Emperor, Fraser's eager daredevil archaeologist has been given an eager daredevil archaeologist son, played by Luke Ford (no relation). Fraser, who at 39 looks perhaps five years older than this kid, needed a wholesome offspring-sidekick like a third arm. Then again, it's not clear that the world needed a third Mummy movie. Director Rob Cohen spends deadening stretches on the backstory, as if under the delusion it's just as important as the mad creepy-crawlies rising out of the sand. Wrong! In a Mummy movie, I want my eyes tickled out of their sockets by frenzied digital overkill and couldn't give less of a hoot about the mummy's ''motivation.''
In this one, he's an evil Chinese emperor who rises up, in the person of Jet Li, as a crumbling oxidized metal ghost whose face keeps chipping off. Fairly cool! After an hour of inert exposition, a race through Shanghai gooses the movie alive. Then it plunges back into torpor, and then, at last, it offers a desert battle of skeletons and rusty soldiers worthy of the sound and fury and utter meaninglessness we want from an orgy of pixels. C