The movie begins when a fiery incident causes Angelina's (Ogie Alcasid) yaya (nanny) to be incapacitated. The girl's parents (Aiko Melendez and Jomari Yllana) search for a new yaya and select Rosalinda "Cha-Cha" Lucero (Michael V.) from a coterie of applicants. Soon, a special love/hate bond is formed between the two. Yaya becomes the object of Angelina's practical jokes and temper tantrums, but she is determined to stick it out with the bratty child. Unfortunately, one final straw breaks her spirit, so she packs her things and move out of Angelina's home. Alone and distraught over Yaya's disappearance, Angelina accidentally discovers a terrorist's (Iza Calzado) plot to assassinate The Duchess of Wellington, who is scheduled to visit her school. The terrorist discovers and kidnaps Angelina; when Yaya learns about her beloved ward's predicament, she sets out to save her. Reunited, they combine their wits to save the foreign dignitary and thwart the terrorists' evil plot.