Martin Lawrence returns as FBI agent Malcolm Turner, a master of disguise who again goes deep undercover as the sassy septuagenarian "Big Momma." The FBI has learned that a computer software developer named Tom Fuller has created a computer virus that allows access to classified US government files, Fuller is planning to sell the virus to terrorist organizations all over the world. Upon hearing this, the FBI's best lead is Fuller's wife. So Malcolm goes undercover again as Big Momma in order to pose as Mrs. Fuller's nanny. and as always, Big Momma once again turns the house upside down.