Harry Potter and the Prisoner of Azkaban: Chapter 5 Summary.
The Dementor
Chapter 5 of Harry Potter and the Prisoner of Azkaban titled “The Dementor,” deals with Harry’s journey back to Hogwarts, the unsettling presence of Dementors searching for Sirius Black, and the introduction of the new Defense Against the Dark Arts teacher, Professor Lupin.
Morning at the Leaky Cauldron
The chapter begins with Harry waking up at the Leaky Cauldron, where Tom, the innkeeper, brings him tea. Harry dresses up and tries to get a disgruntled Hedwig back into her cage.
Ron enters his room, irritated about his brother Percy, who accused him of spilling tea on a photo of his girlfriend, Penelope Clearwater. Harry tries to tell Ron what he overheard about Sirius Black the previous night, but they are interrupted by Fred and George, who come to congratulate Ron on bothering Percy.

During breakfast, Mr. Weasley is deeply absorbed in the Daily Prophet. Mrs. Weasley tells Hermione and Ginny about a love potion she made in her youth, and all of them giggle. As the family starts preparing to leave, Harry does not get a chance to talk to Ron.
Hermione promises to let Crookshanks out on the train, leading to retaliation from Ron, who is worried for Scabbers. Mr. Weasley calls them to the Ministry cars waiting outside, and everyone piles in to begin their journey.
Journey to King’s Cross
The journey to King’s Cross Station in the two Ministry cars is rather uneventful. The Ministry’s cars, driven by wizards in emerald velvet suits looked almost ordinary. However, they were able to maneuver effortlessly through traffic in ways that Uncle Vernon’s car could never.

Upon arrival at King’s Cross, Mr. Weasley keeps Harry close as they move through the station. To avoid Muggle attention, they pass through the barrier to Platform 9¾ in pairs.
Harry and Mr. Weasley go first, followed by the rest of the family. Once on the platform, Percy spots Penelope Clearwater, and Ginny and Harry exchange amused glances at his behavior.
Before boarding the Hogwarts Express, Mr. Weasley pulls Harry aside. He insists that Harry must promise not to go looking for Sirius Black, despite Harry already knowing that Black is after him. Confused about why he would ever seek out a dangerous criminal, Harry reluctantly agrees to Mr. Weasley’s request.
After this conversation, Harry boards the train and immediately seeks out Ron and Hermione to discuss what he has learned.
The Hogwarts Express
The trio initially struggles to find an empty compartment, but finally discovers one near the end of the train. The particular compartment is empty, except for a strange sleeping man in shabby robes. Hermione quickly identifies him as Professor R. J. Lupin, the new Defense Against the Dark Arts teacher, based on the name stamped on his suitcase.

They settle down and begin discussing the situation with Sirius Black. Harry quickly explains what he overheard at the Leaky Cauldron and tells them about Mr. Weasley’s warning. Ron and Hermione are visibly shocked and concerned, emphasizing that no one has ever escaped from Azkaban before. They wonder why Mr Weasley thought Harry would feel the need to go after him, but cannot come to any conclusion.
Just then, a faint whistling sound from Harry’s Sneakoscope interrupts their conversation. Ron retrieves the Sneakoscope, a device that detects untrustworthy people, and wonders if it is faulty. He recalls how it had gone off earlier when he was sending it to Harry. Hermione questions if he was being untrustworthy at the time, and he responds that he wasn’t supposed to be using Errol.
Ron muffles it by wrapping it in one of Harry’s socks and placing it back in the trunk. The group then talks about Hogsmeade, the all-wizarding village near Hogwarts. Hermione is excited to explore its historical significance, while Ron is more interested in the sweets from Honeydukes, a popular sweet shop. Harry, however, explains that he wouldn’t be able to join them, since the Dursleys did not sign his consent form.
Interrupting their conversation, Malfoy and his gang enter the compartment. Malfoy immediately starts to insult Ron, who gets up in anger. However, Malfoy notices Professor Lupin in the compartment and decides to leave before things escalate.
Encounter with the Dementor
As the train heads north, the weather worsens, and it grows dark and stormy outside. Suddenly, the train begins to slow and eventually stops altogether. The lights go out, plunging the train into complete darkness. The trio scuffles around in confusion, and the compartment door opens.
Neville Longbottom enters the compartment, but due to the darkness, falls painfully on Harry’s legs. Harry helps him up by his cloak. Ginny, who came looking for Ron, also joins them. Amidst the confusion, Professor Lupin wakes up, and lights up the compartment. He then asks everyone to stay where they are, and gets up to leave, but the door opens before he can reach it.
A towering, cloaked figure enters their compartment. It takes a deep breath, and Harry feels an intense, overwhelming cold sweep over him. He feels himself drown in the cold, and loses consciousness.
When Harry awakens, he is on the floor of the compartment with Ron and Hermione looking over him worriedly. Harry tells them that he heard screaming, but Ron tells him nobody screamed.

Professor Lupin breaks off an enormous slab of chocolate and gives Harry a piece. He explains that the creature was a Dementor, one of the guards of Azkaban, sent to search the train for Sirius Black. Lupin hands out chocolate to the others as well, to help them recover from the effects of the Dementor.
Harry feels weak and embarrassed for fainting, especially since no one else did.
However, he follows Lupin’s instructions to eat the chocolate and soon feels a bit better.
Aftermath of the Dementor Attack
The train finally arrives at Hogwarts. They are greeted by Hagrid, who leads the first-year students on their traditional boat ride across the lake to Hogwarts. Harry, Ron, and Hermione board one of the carriages that will take them up to the castle, noticing more Dementors stationed at the entrance gates. Harry feels another wave of cold and dread but manages to control it. As they reach the castle, Draco Malfoy confronts Harry, mocking him for fainting in front of the Dementor. Before Harry can retaliate, Professor Lupin arrives and breaks the confrontation.
The trio is then greeted by Professor McGonagall, who ushers Harry and Hermione off to her office. There they are joined by Madam Pomfrey, the school nurse. She talks about the Dementors with Professor McGonagall and suggests Harry should spend the night in the hospital wing, which he refuses. Professor McGonagall dismisses Harry, but says she needs to talk to Hermione about her schedule and has her stay back.
Inside the Great Hall, Professor Dumbledore addresses the students, welcoming them and explaining the presence of the Dementors at Hogwarts. He warns them not to provoke these creatures, as they are dangerous and will not distinguish between threats and students. Dumbledore also introduces the new teachers, Professor Lupin for Defense Against the Dark Arts and Hagrid for Care of Magical Creatures, which is met with a mixed response.
The chapter ends with Harry, Ron, and Hermione going to the Gryffindor tower, anxious by the presence of Dementors and the looming threat of Sirius Black, but also ready to face the challenges of a new school year.