Forever in Blue (2007)

Forever in Blue, the fourth volume in Ann Brashares' series is less about the members of her now-college-age sisterhood putting on their shared Traveling Pants, and more about taking them off. Artistic Lena, theatrical Carmen, boy-crazy Bridget, and punky Tibby no longer fret about innocent crushes and family spats; they contend with pregnancy scares and canoodling with married men during their post-freshman-year summer. Though Brashares has never backed away from tough issues, the girls' final adventure seems particularly rife with emotion. And while some of the entanglements seem repetitious, the motivations behind them are genuinely moving.