I've always been the protective type, the big brother figure even though we're not blood-related. My step-sister, Emily, came into my life when our parents married five years ago. She was this quiet, bookish girl with her nose always buried in some fantasy novel or classic literature.

At 22, she still had that innocent aura about her, wide blue eyes behind those oversized glasses, long wavy brown hair that she tied back in a ponytail, and a wardrobe full of oversized sweaters and jeans that ...