Original: In response to Voldemort 's reappearance , Dumbledore has re-activated the Order of the Phoenix , a secret society which works to defeat Voldemort 's minions and protect his targets . Despite Harry 's description of Voldemort 's recent activities , the Ministry of Magic and many others in the magical world refuse to believe that Voldemort has returned , and are causing a smear campaign against Harry and Dumbledore .
Simplified: At the end , Voldemort comes , but Dumbledore saves Harry from him , and all the other wizards see Voldemort and know Harry is telling the truth .