Harry Potter and the Order of the Phoenix is a movie that is based on the J.K. Rowling novel of the same name. The movie opens with Harry and his cousin Dudley trading barbs at a park. A storm then whips up, and both boys are soon attacked by dementors. Harry is then accused of using magic in front of a muggle. Harry is quickly whisked away to Number 12, Grimmauld Place, where he learns that the Minister of Magic is making a mockery out of him because he does not want the wizarding world to know that Lord Voldemort has returned.
After the trial (in which all charges against Harry are dropped) Harry returns to school, where he meets Professor Umbridge, a woman who is bent on keeping Hogwarts in the dark and under Ministry control. She is instantly hated by everyone.
Meanwhile, Harry is able to see what Voldemort is doing, and with each vision it gets worse and worse. Snape tries to teach Harry to block his mind, but the hatred between the two is so great that it proves completely fruitless. Meanwhile, Dumbledore is refusing to have anything to do with Harry, and contact with the one adult Harry cares for the most, his godfather, is proving to be quite difficult.
After Fred and George fly away in triumph, Harry has a vision that Sirius is being attacked. After Umbridge catches them trying to use her fireplace, Hermione and Harry send her to be attacked by centaurs and, with Neville, Ron, Ginny, and Luna fly off to the ministry.
The fight with Voldemort's forces is long and hard, and in the process Sirius dies. However, Dumbledore shows up in the end and saves the day, though Voldemort does get away. Upon arrival back at the castle, Harry learns the reason he lived the night his parents died: it was his mother's love that saved him.