2000's "Big Momma's House," the only Martin Lawrence comedy that has even been halfway successful, was pleasantly funny and enjoyable for what it was: a commercial, mass-marketed summer trifle. It sometimes takes a bad movie, though, to put into perspective just how valuable a decent one is—even one named "Big Momma's House." Like 2005's "Miss Congeniality 2: Armed and Fabulous" before it, "Big Momma's House 2" is a low-rent rehash of its predecessor, and wholly unnecessary, to boot. What once charmed and tickled the funny bone is no longer sweet or humorous, the original's qualities replaced with dreary plotting, stock characters, and a tedious and strained script.

With a lovely wife in Sherry (Nia Long), a teenage stepson (Jascha Washington), and a baby on the way, FBI agent Malcolm Turner (Martin Lawrence) has begun steering away from field work for safer in-office assignments. This plan changes after Malcolm's former partner is killed. Behind the backs of both Sherry and his fellow agents, Malcolm once again unleashes his Big Momma guise onto the world, this time posing as a nanny to the Fuller family, the patriarch (Mark Moses) of which is somehow linked to both the murder and a potentially catastrophic computer worm virus. While Malcolm (as Big Momma) moves closer to the truth, he ends up bonding with his three charges—15-year-old Molly (Kat Dennings), 8-year-old Carrie (Chloe Grace Moretz) and toddler Andrew (twins Preston and Trevor Shores)—and becoming emotionally invested in the dysfunctional family. If only viewers could grow to care about what happens next in the same way Malcolm cares for the Fullers...

Generically directed by John Whitesell (2003's "Malibu's Most Wanted") with flashes of unbelievable filmmaking incompetence—an outside rear projection as Malcolm and stepson Trent drive during an early scene looks more fake than those used in a 1940s movie—"Big Momma's House 2" is as worn out as the fictional title character's old, lumpy body. What the film is lacking is her signature tell-it-like-it-is sass. Instead, Whitesell and screenwriter Don Rhymer (2005's "The Honeymooners") have cooked up a thoroughly uninteresting and threadbare plot that only loosely pushes along the series of lame, clumsily set up sketches that make up the overlong 99-minute running time.

The kids Malcolm (as Big Momma) is in charge of are of the Screenwriting 101 school of oft-used clichés, the physical comedy (such as a bathing suit-clad Big Momma running on the beach or jumping onto the roof of a speeding car) is either too obvious to get laughs or was ruined by the onslaught of trailers and TV ads, and the relationships between himself and the Fuller family work themselves out in a way that necessitates the story over common logic. There's even a comic-relief family animal to contend with, in this case a depressed Chihuahua that takes a liking to tequila.

The only time Martin Lawrence (2005's "Rebound") has ever shown any spark on the big screen is under the mounds of latex that make up the robust Big Momma, but by repeating many of the same gags of the original picture, he doesn't have much to work with here. Also making a return appearance is Nia Long (2004's "Alfie"), as love interest Sherry. Long's part is relegated to that of a decidedly inglorious glorified cameo, forced to act clingy and paranoid in her brief scenes as she suspects Malcolm of cheating. Would it have been so difficult for Malcolm to be honest from the start and explain that the case was important to him because of the murder of his old partner? Apparently so. The rest of the cast isn't worth mentioning; they're all serviceable, but one gets the impression that they don't really believe in the project. Who could blame them?

You know you're in trouble when a film plagiarizes off of an already very bad movie—in this case, 2005's "The Pacifier"—and everything that fell flat, appeared desperate and didn't amuse there is mercilessly carried over for this ill-advised carbon copy. Alas, just when "Big Momma's House 2" seems to be reaching its finish line, there is still another fifteen minutes to go, complete with a shameful rip-off of the finale from 2000's bouncy cheerleading comedy "Bring It On" and the use of a hip-hop cover of Toni Basil's '80s song "Mickey." At the very least, viewers are spared the obligatory sequence where Sherry goes into labor. So much for small favors.

Too juvenile for adults, too raunchy for youngsters, and completely exempt of the underlying warm-hearted spirit of the moneymaking original, "Big Momma's House 2" has only one reason for existing, and it isn't creative expression. One can only hope audiences don't get bamboozled into handing over their hard-earned greenbacks for this supremely idiotic and worthless sequel. Judging by the weakened evidence here, a third visit from Big Momma would border on inhumane punishment.