What is the summary for Chapter 4 of Harry Potter and the Sorcerer’s Stone?
Chapter Four: The Keeper of the Keys
The knock is heard again at midnight on Harry’s eleventh birthday. Uncle Vernon takes up his gun while a huge man with shaggy black hair knocks down the door. It is Hagrid, the Keeper of Keys and Grounds at Hogwarts: the same man who delivered Harry to the Dursley’s house by motorcycle years ago. Hagrid is happy to see Harry while a confused Harry is thrilled to get his first “slightly squashed” birthday cake. Hagrid is shocked and enraged to hear both that Harry has never heard of Hogwarts School of Witchcraft and Wizardry and that the Dursleys have never told Harry about his parents’ world.
Harry is surprised to learn that he is a wizard, a famous one at that, and is finally allowed to read the letter of acceptance to Hogwarts, much to the chagrin of the Dursleys. Hagrid sends a new letter by owl to inform Dumbledore that Harry has received his letter and becomes enraged again when he learns that Harry thinks his parents died in a car crash. Hagrid then tells Harry that his parents were killed by the evil wizard, Voldemort, and that Harry himself survived with only the scar on his forehead while Voldemort lost all his power. Harry can’t believe all of this news until Hagrid mentions all of the strange things that happen in Harry’s favor that Harry has never been able to explain.
Meanwhile, Uncle Vernon continues to throw insults at Harry’s family, refusing Harry’s entrance into Hogwarts. When Uncle Vernon insults Dumbledore, Hagrid snaps. Using magic, Hagrid gives Dudley a pig’s tail. The Dursleys leave the picture, cowering over their “injured” son. Hagrid and Harry plan to leave in order to get Harry’s special school supplies for the year.
Uncle Vernon takes his family to an isolated cabin. The door is pounded upon during the stormy night. Hagrid knocks it off its hinges and strides inside. He has reached Harry at the “Hovel.” He is a giant man, with bushy black hair and beard. Vernon points a gun at him, but Hagrid bends the barrel and throws it into a corner. Hagrid is head gamekeeper and Keeper of the Keys at Hogwarts. Hagrid delivers the Hogwarts admission letter to Harry and tells Harry the truth about how his parents died and the terrible reign of “He who shall not be named.” After Vernon shouts out that he won't pay to have a "crackpot old fool" teach Harry "magic tricks," Hagrid loses his temper and points his pink umbrella at Dudley. The boy yells out, and he now has a pigtail growing out of his behind! Hagrid, who was expelled from Hogwarts years ago for some reason, had his wand broken in half and still keeps it inside his umbrella. The next morning, Harry begins to discover the “wizarding world," with Hagrid as his guide. Hagrid takes Harry to the Leaky Cauldron, in London. It is a pub few muggles ever notice. Before moving on, Harry's hands are pumped, and he's eagerly greeted by many witches and wizards who are well aware of his fame that he is only beginning to discover. Hagrid introduces him to a shaky, stuttering man named Quirrell, whom the big man says will be Harry's Defense the Dark Arts professor come fall.