Star Split, by Kathryn Lasky, is the story of thirteen-year-old Darci. She lives in a world powered by genetic engineering and the Bio Union. Darci happens to love rock climbing, but it will be this very thing that will change her life for the better or the worse. As Darci is relaxing on a rock face, she suddenly comes face-to-face with an umbula (clone) of herself! The umbula's name is Vivian, and they both soon realize that they can never, ever be seen together. However, soon both Darci's and Vivian's worlds are turned upside down, and each hour brings them closer to death.
I loved this book! It was a suspenseful thriller packed with science, and it made me want to find out more about the subject.