Emma Rose is ten years old. She has four best friends and an older sister who loves to play pranks on her. She is as normal as a girl can be. Until the morning when she wakes up with blue streaks in her hair. At first, she thinks it is another of her sister's pranks. But when she gets to school, she finds out that her friends have streaks in their hair, too--red, green, purple, white. What's worse, they all have magical powers. Emma has to get to the bottom of this. An old book leads her and her friends to a secret island in the Florida Keys. There they find a queen in a chocolate castle. The queen agrees to teach them about their new powers. Little do they know that this is just the beginning of the adventures of the power girls.