Annie (Kristen Wiig) is a single woman whose own life is a mess, but when she learns that her lifelong best friend, Lillian (Maya Rudolph), is engaged, she has no choice but to serve as the maid of honor. Though lovelorn and almost penniless, Annie, nevertheless, winds her way through the strange and expensive rituals associated with her job as the bride's go-to gal. Determined to make things perfect, she gamely leads Lillian and the other bridesmaids down the wild road to the wedding.