Complex sentence: Lena Kaligaris, Tibby Rollins, Bridget Vreeland, and Carmen Lowell, who will be spending their first summer apart when a magical pair of jeans comes into their lives, turning their summer upside down.
Split into simpler sentences: Lena Kaligaris, Tibby Rollins, Bridget Vreeland, and Carmen Lowell, who will be spending their first summer apart. When a magical pair of jeans comes into their lives, their summer turns upside down.