When the Budlow family hire a live-in housekeeper, Mrs. Stanton, she proves to be more than they expected. She notes from the start that the others all mistreat the youngest son, Craig, ten, who wishes that the Payback Phantom, someone inconspicuous but effective who gives them a taste of your own medicine that he has heard of would come and do the job.When each family member gets a dose of what they give Craig in a parallel situation at the office, at school, or in some social situation Mrs. Stanton makes no apology for saying they deserved it and need more of that until they learn the lesson of respecting everyone. In some cases those embarrassments are because of what she did - like sew lace trim on the older son's gym shorts. When Craig asks her if she is a payback phantom she doesn't deny it.When Craig receives an award at school Mrs. Stanton demands that the whole family attend - as they did for his brother and sister. At that event a confused and disturbed woman with a gun intent on avenging her dead sons enters the school and grabs Craig as the one responsible. Mrs. Stanton must try to make her see that she has misidentified the boy and his family as the culprits because of a similarity in names and try to keep anyone from getting hurt while the police sneak in a sniper to shoot the armed person - who has been misidentified to them as Mrs. Stanton.