The president of the United States was shot and killed while attending the award ceremony of the National Honor Awards held by a university.... As an ace agent responsible for protecting the safety of important American leaders, Alex felt so guilty about her dereliction of duty that she anesthetized herself with alcohol all day long. Kate, a female journalist in charge of reporting the case, accidentally found a clue to find the real killer, however, there always seemed to be someone monitoring her whereabouts, and everyone who provided her with clues died strangely. In desperation, she had to turn to Alex for help; but they were attacked by a mysterious man on the day they met and almost died. As a result, Alex strengthened his determination to find out the truth, so he and Kate began a journey full of difficulties and obstacles, and finally uncovered the evil plot behind the assassination of the president.