Belinda dragged her hostage upstairs up to the top floor. It was a good distance from the crowd downstairs and they had backed up quite far. The gun she had could not shoot that far, so she would not hit anyone even if she fired. All she could do was threaten the crowd that if anyone approached the door, she would fire. If she fired at the door from the top floor, she could still hit someone.
The hostage was knocked out, so she could free a hand to call Mr. Gordon and get him to save her. If sh