Harry Potter And The Rose Hathaway

The story takes place right after Shadow Kiss. Only Dimitri stayed a Dhampir and he and Rose can be together because Rose and Lissa sent to Hogwarts. Over there it's been a year sense the war and all the students stayed a year. Rose and Lisse meets Harry Ron and Hermione and they become great friends and everything looked promising. Until she gets a massage from school that Dimitri has been poisoned. He is dying on a one of the med clinic's beds suffering with pain. And the cure will be giving only in one cost. Her life. Who are these people? What they want from Rose and Dimitri? And what it is have to do with Harry?