As their lives take them in different directions, Lena, Tibby, Carmen, and Bridget discover many more things about themselves and the importance of their relationship with each other.

With a bit of last summer's sand in the pockets, the Traveling Pants and the Sisterhood that wears them embark on their 16th summer. Bridget: Impulsively sets off for Alabama, wanting to both confront her demons about her family and avoid them all at once. Lena: Spends a blissful week with Kostos, making the unexplainable silence that follows his visit even more painful. Carmen: Is concerned that her mother is making a fool of herself over a man....

Jamie Kelly writes in her diary about her new jeans, which seemingly cause events that affect both her popularity and her efforts to get close to the eighth cutest boy in school, Hudson Rivers.

Rooster is so excited when his new skinny jeans arrive, but the other animals' reactions to his stunning new style is not what he expected.