Massie Block is the leader of a small group of privileged schoolgirls who arrogantly call themselves 'The Pretty Committee'. These so-called pre-teen 'mean girls' (cynical, egotistical, selfish and narcissistic females) and their clique are respected and feared in their middle school as well as their upper class Rhode Island suburban neighborhood. But Massie's life takes an unexpected turn when her parents friends, a lower-middle class family with a self-assured daughter named Claire move into the Block's guest house and Claire threatens to undermine the superficial Massie's position of the clique.