FBI agent Malcolm Turner (Martin Lawrence), along with his partner, John (Paul Giamatti), have just been handed their next case: a stakeout way down in the heart of Cartersville, Georgia, with their subject being Hattie Mae Pierce, aka Big Momma (Ella Mitchell), a robust 350-LB. old lady. It seems a convicted killer and bank robber (Terrence Howard) has just escaped from prison, and his ex-girlfriend, Sherry (Nia Long), is on his short list of people he wants to do away with. Sherry, who has a young son (Jascha Washington) and may or may not have been involved in the bank robbery, flees from her home after news arises about his breakout, and sets off for Big Momma's house, her grandmother whom she hasn't seen since she was a child.

Problems arise when Big Momma gets a distressing call from a friend and leaves for a few weeks, leaving the house empty. Malcolm realizes that their plans will be ruined if Big Momma isn't there for Sherry's arrival, so he does what any normal master of disguise would do: he single-handedly must convince everyone in the town that he is Big Momma.

"Big Momma's House" takes an obvious, one-joke premise that might have grown old very quickly, and with the aid of Darryl Quarles' and Don Rhymer's screenplay, successfully creates variations of the joke for 97 minutes. From a brilliantly edited childbirth scene (with Big Momma as the midwife) to one in which Big Momma makes dinner with several pounds of lard dumped into a pan, the laughs are usually plentiful and distract the mind away from the film's shortcomings in several other areas.

As a simple comedy, "Big Momma's House" does its job professionally and aims to be nothing more than an unoriginal entertainment. However, its storyline has been recycled an innumerable amount of times, and it was easily predicted where the plot was going at every moment. For example, it is a given that, by film's end, everyone will discover the true identity of "Big Momma" with the arrival home of the real Big Momma. And when Malcolm, and not "Big Momma," has a Meet-Cute scene with Sherry and her son, it is only a matter of time before the inevitable romance ensues. The total insistence on following the stringently laid-out formula seems just upon the edge of growing tiresome throughout, but is saved because, regardless, the comedy still works.

Martin Lawrence (1999's "Blue Streak"), who normally comes off (to me, at least) as a poor man's Eddie Murphy, or even Chris Tucker, finally gets it right this time, as he is given the chance to stretch beyond his relative blandness and play a character playing a character who is as physically different from him as could be. Whereas Malcolm is a stock character with few defining qualities, Lawrence's portrayal of Big Momma (which takes up about 80% of the running time) is endearing and believable. There were more than a few times, in fact, when it was easy to forget Lawrence's Big Momma wasn't a real character.

Nia Long (1999's "The Best Man") has been garnering quite a lot of work lately, and with last spring's "Boiler Room" and now "Big Momma's House," she is doing something few African American actresses do, and that is get away from the limited roles offered in demographically black-targeted films and break out into the mainstream. Since 1993's "Made in America," Long has been a big talent worth watching, and seven years later, she is finally, and rightfully, getting the opportunities she deserves. As Sherry, Long's role isn't particularly demanding here, but it is the type of sweet-natured part that has a sizable chance of getting her noticed.

In supporting roles, Paul Giamatti amiably stars as John, Malcolm's partner; Terrence Howard is wasted as Sherry's criminal ex-boyfriend who is after her, with only a handful of lines of dialogue; Jascha Washington escapes from the unctuousness that plagues the majority of child actors, and is naturally likable; and Ella Mitchell, as the real Big Momma, is astoundingly funny, allowing her comedic skills to shine with giddy aplomb.

"Big Momma's House" isn't great cinema, and it isn't even a great comedy. Despite its downfalls, though, one thing cannot be denied: it is consistently funny and I had a good time. There is a time and place for innovation in motion pictures, and then there is a time for movies you know going in what will happen. The sense of knowing sometimes even has a sort of charm about it, since it is the treatment that matters, rather than the payoff. "Big Momma's House" offers energy to spare, a lot of laughs, and a performer (Lawrence) who comes into his own and gets to show why he is fast becoming a big star. The film's payoff may not be particularly satisfying, but its treatment surely is.