Yaks, as everyone knows, are relatively unintelligent. So you have to wonder at the utter idiocy of the hero of this movie yelling at a yak to “Live free!” (and “die well”), with the entire unmoving act accompanied by inspirational music. The scene opens with a bunch of mountains and absolutely nothing else. Then you see the heroes melodramatically struggling up a mountain. You wonder why they are stumbling, listing violently from side to side, using walking sticks. ­Finally you realize that there is a snowstorm, which somehow escaped your (and the camera's) notice. The heroes yell some epic lines like “We've reached it!” above the (strangely silent) wind. You contemplate ejecting the DVD.

This is how you will feel if you watch “Tomb of the Dragon Emperor,” the fourth installment of the Mummy movies. It is a perfect example of a series that steadily degenerates in quality. Its plotline ­resembles “The Mummy” and about a million other movies: an evil villain from ancient times comes back to life, and our heroes must save the world from his wicked plot.

“Tomb of the Dragon Emperor” is basically the ancient Chinese version of “The Mummy.” Just replace the mummies of doom with terracotta soldiers and the undead Egyptian priest with an undead Chinese emperor. Jet Li plays Emperor Han, who seeks out a witch to attain immortality. Instead, she traps him in a curse. And so the O'Connells – like good little ignorant heroes – manage to awaken him and help start his quest of revenge on the world … oh, and the witch too.

Enter our saviors again: old-time mummy fighters Richard “Rick” O'Connell (Brendan Fraser, who could have gotten a better job than being the protagonist of this movie), his wife Evelyn (Maria Bello), their son Alex (Luke Ford, who looks just as old as his parents), and Evelyn's brother, Jonathan (John Hannah).

All in all, “Tomb of the Dragon Emperor” did not merit being turned into a movie. The tale of Emperor Han is almost exactly that of Imhotep, the undead villain of “The Mummy”: a love triangle between two important guys and one important girl that ends up with someone important getting cursed, except the villain's character has no depth. Unlike with Imhotep, you can't identify with the ­Emperor.

As for the other characters, Alex's love life is very clichéd; you can tell from the start what will happen. Also, Rick, Evelyn, and Alex are played pretty badly – there's no chemistry between them anymore. If you watched the movie on mute, you would have no idea that Rick and Evelyn are supposed to be in love, and that Alex is their son.

“Tomb of the Dragon ­Emperor” has a predictable, overused plot and, unlike the previous two films, no humor or horror. The parts that are supposed to be funny or ironic fall flat – especially the subtitle at the end, and the villain ­doesn't have the same menacing this-is-the-end-of-the-world aura that Imhotep had. His Mandarin is barely understandable, and the captions aren't as accurate as they could be.

If you're considering watching “Tomb of the Dragon Emperor,” try something more entertaining and original … like “Dragon Tales.”