Harry Potter And The Prisoner Of Azkaban, there are many things I can't understand about this movie. Can someone answer them for me?

It is a terrible thing to spend the summer vacation in a menstrual home. Harry Potter not only left his good friend, but also had to be tortured by muggles all day. Until he 13 years old, everything changed completely. Early that morning, Harry received birthday presents from his friends Hermione and Ron. He looked very happy. Coincidentally, from this day on, Margo's menstruation will stay here for a week. She angered Harry, so Harry turned her into a balloon and flew into the sky.

Harry escaped from the menstruating house by himself. In the middle of the night, he was walking alone in the street when he suddenly saw a terrible black dog. Fortunately, a knight bus from the magical world arrived in time, rescued Harry and took him to London. Harry had a happy time in London. He not only saw many strange magic objects, but also finished his own paper. Strangely, he also met a book called "Death Signs", the cover of which was the black dog he saw the night he left his menstrual home. A sense of foreboding made Harry feel that something terrible would happen.

At the end of the summer vacation, Harry also met his two good friends Hermione and Ron in London. Harry learned a terrible thing from them. Sirius, the villain who is said to have betrayed his parents, escaped from Azkaban, and his purpose is probably to continue to hurt Harry.

Harry was not afraid when he heard that Sirius was going to hurt himself. On the train back to Hogwarts School of Witchcraft and Wizardry, he met dementors, a monster that gave him the creeps. It was sent by Azkaban prison to arrest Sirius, and Harry Potter fainted every time he met a dementor. Fortunately, the new magic teacher Professor Lu Ping helped Harry.

Harry Potter and his two good friends Ron and Hermione are entering the third year of Hogwarts School of Witchcraft and Wizardry. These teenagers are forced to face their greatest fears and deal with a dangerous fugitive and a group of dementors who are supposed to protect him.

The school of witchcraft and wizardry has started again, and many new students have come. Harry also went back to his classmates and friends. The new teacher's new curriculum has made his life fresh and exciting. The new magic teacher Lu Bang's class is very interesting, but the divination class makes Harry feel even more afraid. Snape is still against him as before. Interestingly, Hagrid also became a teacher and taught them to keep some strange animals. One day, Hagrid taught them to get close to Buckbeak (a huge, fierce and grumpy Gryphon), and Malfoy angered him, so Buckbeak kicked Malfoy.

Malfoy, who was wounded by Buckbeak, immediately reported Hagrid to the Ministry of Magic. He wants to disqualify Hagrid from teaching and execute Buckbeak the Gryphon. On the day Buckbeak was executed, Harry, Hermione and Ron came to Hagrid's cabin. They want to comfort Hagrid. Unexpectedly, instead of finding Hagrid in the hut, they found a mysterious black dog and Ron's pet mouse.

Harry and the three of them curiously followed the black dog and Scabber and found that they got into a hidden cave, so they climbed in. After climbing a dark road, Harry and others came to a small house. They were suddenly startled: in the room, a unkempt man was fighting with a dwarf and Professor Snape. Professor Snape told Harry that the unkempt man was Sirius who killed Harry's parents.

Seeing the enemy who killed his parents, Harry waved his wand angrily and pointed it at Sirius. At this critical moment, a man suddenly rushed into the room and knocked Harry to the ground. This man is a magic teacher, Professor Lu Bang. It turns out that Sirius is not the one who killed Harry's parents. In fact, the real murderer is the mouse that has been lurking around Ron. This mouse is actually peter pettigrew, another friend of Zhan Mu and Lily.

At school, Zhan Mu, Sirius, Lu Bang and peter pettigrew were all good friends. Because of Lubang's werewolf status, the other three good friends managed to learn Anima Gus, a magic that can turn themselves into animals. Zhan Mu is a stag (in the form of Harry's patron saint), Sirius is a big dog, and Pettigrew becomes a mouse. When the moon is full, Lubang becomes a wolf, Zhan Mu and Sirius become stags and big dogs to fight it to prevent it from hurting others, while Pettigrew's mouse runs to whomping willow and presses the static switch, so that it can reach the legendary haunted "screaming hut" through a secret passage, so that Lubang can stay away from the crowd and spend that difficult night. Lubang was not rejected by his good friend because he was a werewolf. On the contrary, he has been protected by Zhan Mu and Sirius. Pettigrew, on the other hand, is always flattered by friends like Zhan Mu and Sirius.

When Voldemort came to power, all members of the Order of the Phoenix, including Zhan Mu and Lily, went underground to work. Harry was just born. Zhan Mu and Lily live in a secret place in Godric Valley. Their hiding place is protected by the "red loyalty curse", and their good friend Sirius becomes their secret guardian. The situation was very dangerous. Sirius fears that his identity as a secret guardian will be used by Voldemort to harm Zhan Mu and Lily. So, he made a decision, that is, let the humble peter pettigrew replace him as the secret guardian of Zhan Mu and Lily. He thought Pettigrew would not attract Voldemort's attention. However, Pettigrew's natural cowardice and timidity made him succumb to Voldemort. He sold his soul and became a servant of Voldemort. He told Voldemort where Zhan Mu and Lily were hiding. Zhan Mu and Lily died, but little Harry survived. Voldemort became a wandering soul floating on earth.