Well, apart from the numerous tense errors, this is fine. In fact, it's actually rather good. The ending was, well, unexpected. Good job. Keep it up! (:
I really liked your story. The twist-ending was nice. It was also writen very well. And finally, I wanted to say thanx for reviewing one of my stories- In Joy and Sorrow. ^_^
Good job of making Radcliffe seem utterly charming up until the end. You had some grammatical errors, but they either dissapeared or became less noticable a the story went on. Good premise, you just need to do a bit of proofreading.