'This is the weapon he has been seeking so assiduously since his return: the knowledge of how to destroy you' Albus DumbledoreHarry Potter is furious that he has been abandoned at the Dursleys' house
Harry is furious that he has been abandoned at the Dursleys' house for the summer, for he suspects that Voldemort is gathering an army, that he himself could be attacked, and that his so-called friend
