FBI agent Malcolm Turner is elated to learn that his stepson, Trent Pierce, has been accepted to attend
Duke University. However, Trent, who is a rapper under the alias "Prodi-G", instead wants Malcolm to sign a recording contract for him since he is underage. When Malcolm refuses, Trent's best friends encourage him to ambush Malcolm on the job in order to obtain the signature. Malcolm, in an attempt to capture Russian gang member Chirkoff, uses an informant named Canetti to deliver a
flash drive to the gang. Canetti reveals that the flash drive is empty and a duplicate is hidden with a friend at the Georgia Girls School for the Arts. During the exchange, Canetti's cover is blown and he is killed, which Trent witnesses. Malcolm eventually rescues Trent and they escape, but as Trent's car was left at the scene Malcolm knows the gang members will be able to track them down so the two are forced to hide undercover. Malcolm once again becomes his wife Sherry's grandmother, Big Momma, and also disguises Trent as an obese girl named "Charmaine", Big Momma's great-niece. Big Momma takes a job as a house mother at the school, while Charmaine is enrolled as a student. Surrounded by attractive young women, Trent nearly blows his cover, but befriends a girl named Haley Robinson. The headmistress announces that a historic music box has been stolen from the library, and Malcolm deduces that it contains the flash drive. While scoping out the library, Malcolm encounters security guard Kurtis Kool, who attempts to woo him while giving a tour. Seeing a picture of Kurtis with Canetti, Malcolm realizes that he is the friend, and tries to find out more about the music box. Meanwhile, the gang members approach Trent's best friends, posing as record producers, and encourage them to notify them of Trent's whereabouts. Trent sets up a date between Haley; he reverts to his true self and the date goes well, but an encounter with his best friends alerts the gang members to tail them. Trent helps Haley perfect her musical performance for the upcoming "Showcase" event, turning it into a duet. They exchange a kiss at the end of the date, while Haley encourages Trent to pursue college. Before the gang members can capture him, he changes back into his Charmaine disguise, throwing them off. Learning of an exchange between two students and Kurtis, Malcolm attempts to flirt with him in order to apprehend him for stealing the music box, but the secret exchange ends up being the stolen
mascot from a rival school. During this encounter, Malcolm reveals his true identity to Kurtis. After gaining the favor of several students by offering sage advice and comfort to them, he finally learns the music box was actually stolen by Haley. She did it to become a full-fledged member of the "Divas", a group of top artists in the school. As she is about to perform her duet, Malcolm forces Trent to retain his disguise, and he attempts to perform the duet with Haley as Charmaine, only to break disguise and ruin the performance. As Haley storms off, the gang members arrive and a chase ensues. Trent accidentally draws their attention as he attempts to pursue Haley and explain himself. Just as he recovers the flash drive, the gang members catch up and hold him at gunpoint. Big Momma interferes and provides an escape, but all three are caught again and Malcolm's disguise is revealed. Just as Chirkoff is about to kill them, Kurtis arrives with a taser and saves the day. Trent and Haley reconcile, and Malcolm signs the former's contract, only to have him tear it up and reveal his new plan to attend college. As the film ends, Malcolm and Trent make an agreement to keep the whole ordeal a secret from Sherry. ==Cast==