Malcolm Turner’s teenage stepson Trent Pierce has just graduated from high school and is accepted into Duke University. However, he prefers to pass on college and pursue a music career as a rapper named “Prodi-G.” With his mother Sherry away on vacation, Trent tries to get Malcolm to sign a contract for him but Malcolm refuses as he believes that Trent should get his education. Persistent to get the signature, Trent stalks Malcolm while he is working on a case and witnesses a murder. To keep Trent safe, Malcolm goes undercover as Big Momma for the third time. Trent joins him, going undercover as Big Momma’s great niece “Charmaine Daisy Pierce” at a performing arts’ school for girls. Trent tries to develop a romance with one of the girls as himself while “Big Momma” is being pursued by the school’s goofball Marine, Kurtis Kool.