Proof

When the friend she loved like a sister died a suspicious death, Alex, a female FBI agent, did everything she could to find the truth, but her investigations were always preceded by a mysterious man. Is he friend or foe? He was the man who, 15 years ago, infiltrated Alex's alma mater, the elite boarding school for girls, Athena Academy, and made the girls' hearts flutter as the mysterious Dark Angel, becoming a legend. He was also Alex's first love. But why did the Dark Angel show up at our alma mater again?