Harry snapped into action, "You are going to send her away," he whispered harshly, his wand pointed threateningly at a defiant Snape, "and if you won’t, then you best believe that I will  make you," Snape’s eyebrows drew together in incredulous amusement, as if he very much doubted that Harry could make him do anything, "and if you don’t believe me then you are in for a  nasty surprise. The Imperius curse requires the castor to truly mean it, and by Merlin I’ve never meant anything more in my entire life. If you think that your strength of will is superior to mine then prepare yourself for bitter disappointment," Snape looked him, frozen, a hint of reluctant fear in the corner of his eye despite his obvious contempt.