Files of Sapphire Michaels

Sapphire's life had just began to go uphill. The past few months Sapphire had to watch her mischevious younger brother and sister while studying for exams, because her parents were busy working. What work? She never knew . Then one day after going out with a friend she comes home and her parents are almost dead. Right before they die they tell her something " Save the family and use the book." Then days later Sapphire is able to control nature and her sibling can control fire and water. What is happening to Sapphire? What is the book? Who killed her parents? What will happen to the rest of her family?