Three geeky, thirty-something women--all lifelong friends--decide to break the monotony of their boring lives and take a vacation to South Padre, a popular Spring Break destination. Before they leave, however, Becky (Parker Posey), who works for a senator (Jane Lynch), is asked to keep an eye on her boss' daughter, Lindsay (Amber Tamblyn), to make sure that the supposedly wild child does not get too out of control on Spring Break. But when Becky and her friends (Amy Poehler and Rachel Dratch) discover that Lindsay is not the party animal she seems, and is in fact even geekier than themselves, they realize that this is the perfect time to act like the wild girls they always wanted to be.