Mary is a free-spirited young woman with a run-down New York apartment and a high-fashion wardrobe. She calls her godmother, a librarian, for bail money after being arrested for throwing an illegal party. To repay the loan, she begins working as a library clerk. At first she hates it, but when challenged she decides to master the Dewey Decimal System and become a great library clerk, while romancing a falafel vendor and helping her roommate become a professional DJ.