Thirteen-year-old Casey's mother always said that Casey's sixteen-year-old sister marched to the beat of a different drummer. But it isn't until Briana runs away with an older boy that Casey begins to understand what her mother meant. When Briana returns home alone and pregnant, Casey and her mother try to help Briana come to terms with her options. It was already complicated to think about Briana's choices and then things change suddenly again. When Briana is in a serious accident, Casey's mother sees things one way. Although Casey understands her mother's reaction, she feels she must try to convince her mother to make a different decision. Casey needs to grow up fast and do what she can to maintain Briana's legacy. Will she be able to make her mother understand that there is only one way to accept Briana's gift?
