During the summer holidays, Harry is happily anticipating his escape to the local public school in September, which will not only get him away from his thuggish cousin Dudley (whom the Dursleys are sending to an exclusive, private academy) but will also allow him his first taste of freedom. A mystery presents itself, however, when, a few days prior to his eleventh birthday, letters addressed to Harry, in "The Cupboard Under the Stairs"-Harry, who never receives mail of his own-begin arriving at Privet Drive. Uncle Vernon-who, along with Aunt Petunia, seems terrified by the first letter's arrival-prevents Harry from reading it, and does his best to intercept the subsequent letters. Uncle Vernon moves Harry into Dudley's second bedroom, in hopes that the mail cannot be properly addressed-and yet the next envelope is addressed to "The Smallest Bedroom, 4 Privet Drive." Uncle Vernon nails the mail slot shut, but a dozen letters force their way into the house. Even on Sunday, when no postal service operates, letters for Harry fly down the chimney. In desperation-on the day before Harry's birthday-Uncle Vernon packs up the family and takes everyone to a shack on a rock out at sea. The family rows out to the shack, just ahead of a brewing storm. Harry, aware that his birthday is approaching and consumed by the mystery of the letters, cannot sleep as the storm rages outside; he counts down the minutes until he will be eleven years old. And at exactly the first moment of Harry's birthday, someone outside the shack loudly knocks at the door.
Rowling strikes notes of foreshadowing and irony as Chapter 3 opens: although Dudley will be attending an exclusive, private school, Harry will end up attending a school even more exclusive and special. The author also displays her command of comedy, as both the persistence of the letters and the determined but futile attempts of Uncle Vernon to stop their arrival grow throughout the chapter. While the text makes for enjoyable reading, it also serves the purpose of moving readers further out of the Muggle world and further into the magical one, even as Harry and the Dursleys (in spite of themselves) move further out of their insular, ordinary existence at Privet Drive.