This followup to the 2000 period buddy comedy that incongruously paired Jackie Chan and Owen Wilson suffers from a nearly fatal case of sequelistis. “Shanghai Knights” is a more sumptuous, lavish picture that “Shanghai Noon” was–Allan Cameron’s production design is often elegant, and it’s all been filmed in bright, crisp tones by Adrian Biddle (though some of the process establishing shots are rather phony). The period convolutions of the script are more elaborate, too. But it’s a lot less amusing; even the title can’t hold a candle to its predecessor’s witty moniker.

The movie is set a few years after the end of the original; Chon Wang is sheriff of Carson City, and Roy O’Bannon a roguish fop leading the high life on credit in New York. When word reaches Wang that his father, the keeper of the Chinese imperial seal, has been killed and the great seal itself stolen, he hastens to New York to retrieve funds that O’Bannon has supposedly invested for him in order to travel to London, where he’s going to help his sister Lin take vengeance on the killers and retrieve the emperor’s property. Naturally this leads to a series of supposedly hilarious complications, mostly due to Roy’s ineptitude and penchant for braggadocio, in both New York and London. There are also lots of choreographed fights in the usual Chan mode, plus plenty of slapstick and action involving historical personages and threats against the British crown (in the person of Queen Victoria) as well as against the emperor of China. None of it makes much sense, of course, but that’s in the nature of nonsense–an amusing example of which is what the picture aims to be.

Not surprisingly, the best parts are the more imaginative of Chan’s routines, in particular one in which he uses umbrellas as props and does a parody of Gene Kelly’s famous “Singin’ In the Rain” number, and another in which supposedly valuable vases play an important role. But to be honest, though Chan remains remarkably nimble and fleet for a guy approaching fifty, his other set-pieces aren’t nearly as impressive–a climactic sword fight, for example, is merely repetitive and curiously dull. To add to the woes, the repartee between the leads is almost painfully flat. That’s not just because Chan’s command of English inflection remains poor, but because the material given to Wilson is simply dreadful. (It’s amazing, for instance, that he’s compelled to do one of the oldest routines in the book as a tourist annoying one of those supposedly unflappable guards at the palace gates. Even a comic as shameless as the late Milton Berle would have been embarrassed to resurrect the old chestnut, but it’s disinterred here without apology.) And the anachronistic surfer-dude delivery that had a certain charm in the initial installment is a distinctly old joke this time around. The picture doesn’t have a good villain, either: Aidan Gillen does a pallid imitation of Gary Oldman as the wicked British nobleman Rathbone. (At one point, the plot thread involving him promises a reprise of “Kind Hearts and Coronets,” but the idea quickly vanishes.) Arnold Johnson seems a British Crispin Glover as Arthur Conan Doyle, with whom the boys fall in, and Fann Wong is photogenic but little more as Wang’s sister–though her athletic feats are striking.

The end result is that despite its polished surface, “Shanghai Knights” stumbles more often than it flies. If one wants to be kind he can point out that it’s better than “The Wild Wild West,” but that’s not saying much. When the more tedious bits of the picture cut in, though, a viewer can always amuse himself by toting up the historical howlers it purveys. The script does get the year of Queen Victoria’s jubilee correct at 1887, and it’s just barely possible that the first Sherlock Holmes story, published in that year, might have been inspired by Conan Doyle’s encounter with the likes of Wang and O’Bannon. It’s also feasible that telephones would have been found in a New York hotel by that year. But having Rathbone tool around the streets of London in a spiffy automobile is clearly absurd (Benz’s first prototype had only appeared two years earlier). Similarly, showing Whitechapel terrorized by Jack the Ripper at least a year before his murder spree began is a flub, as is depicting Charlie Chaplin as an Artful Dodgerlike street urchin two years before he was actually born. One shouldn’t be too hard on the screenwriters for these sorts of faux pas, of course; “Shanghai Knights” is designed as a comic concatenation of cultural artifacts, not a history lesson. Unfortunately, it’s also intended to be a jaunty, loose-limbed send-up of the action-adventure genre, and one can rightfully complain of how rarely it succeeds on that score.