Amber Tamblyn, America Ferrera, Blake Lively and Alexis Bledel reunite onscreen this summer as the lifelong best friends audiences fell in love with four years ago. Based on Ann Brashares’ best-selling series of novels about four young women who share an unbreakable bond through the unpredictable events of their lives, “The Sisterhood of the Traveling Pants 2” catches up with Tibby, Carmen, Bridget and Lena in the months following their first year of college. Having been apart all year, their plans for the summer will take them even further along separate paths as each experiences the freedom, love, choices and challenging life lessons that mark their individual journeys toward adulthood. Now, it will take more than a hurried note or even a treasured pair of pants passed back and forth among them to keep their lives connected.