The best mystery that I have ever read was "The Speckled Band" by Sir Arthor Conan Doyle. I have a younger sister, and I can relate to the family aspect of the story. I loved how the red herring in the middle of the story kept you on your toes. I was really caught up in the suspense. I could not put the story down.
Mystery starter: I woke up and immediately looked at my wall. Something was wrong. To my horror, I saw that the medal was gone! All that I had worked for, the long training sessions, my blood, sweat, and tears, GONE! The question now is who did it.