Will Smith and especially Tommy Lee Jones, returning as the ultra-secret, ultra-hip MIB agents fighting the alien threat, are never uninteresting to watch. The rapid-fire special effects and array of bizarre creatures help the film's 88 minutes speed by. And mascot pug Frank gets more screen time.

But story here is both muddled and lame. Agent Jay (Smith) emerges early on to tangle with a giant snake monster that threatens subway riders. Meanwhile, in a plot device previously devised by Richard Wagner and Tolkien and also currently on view in The Dangerous Lives of Altar Boys, evil dragon-lady Serleena (Lara Flynn Boyle) has landed in New York to retrieve that proverbial magical object (here a bracelet, not a ring) that will give her world power.

In his quest to help save the world, Jay encounters important clues and romance at a SoHo pizza establishment, where worker Laura Vasquez (Rosario Dawson) has reported an alien sighting--her boss--that could lead to Serleena. Jay then seeks out former colleague Kay (Jones), who, with his agent past erased, now serves as postmaster in coastal Truro, Massachusetts. Maybe it's the lazy summer season, but Jay has a tough time luring Kay away from sunny Cape Cod and getting his memory restored.

That done and with blabbermouth pug Frank by their side, the star agents, working under MIB boss Zed (Rip Torn), follow a path of clues that takes them to a Grand Central Station locker. Perhaps in an effort to jack up the film's budget by many millions, the locker opens onto a vast alien gathering. Other stops include a video store with a mamma's-boy proprietor and an ordinary apartment revealed to hide the black-suited agents' vast cache of trademark shiny weapons.

Smith's Jay is likeable, but Jones' Kay, with not much to do here, is less hero agent than fine, intelligent actor phoning in for big bucks. Cameos from Martha Stewart, Michael Jackson, Peter Graves and director Sonnenfeld add no more than fleeting surprise.

As sequels go, the kid-friendly MIB II disappoints. The wit, drollness and cool of the debut installment are largely gone, as is the novelty of the original. The expanded role of pug Frank is welcome, but next time around the filmmakers might want to consider the Boston terrier--already nattily suited up in cool black and white and offering, by way of nature, not digital trickery, a broader array of facial expressions.