Petunia's explaination about Dementors and Azkaban not only shocks her family, but shows she knows more about the wizarding world than she has let on. Harry leaps to the conclusion that the Howler she received by Aunt Petunia has comecame from Dumbledore; this is fuelled largely by wishful thinking, as Harry has been hoping for a communication from Dumbledore all summer and has not received anything. However, if the Howler is from Dumbledore, it implies that Petunia has had more communication with Albus Dumbledorehim than has yet been revealed.
That Harry would be expelled from school and have his wand broken, without therean first being anofficial inquiry, indicates the Ministry of Magic may have some ulterior motive in moving so quickly against him. Obviously, others (apparently including Dumbledore) have intervened on his behalf to prevent this, and a hearing has been scheduled to allow Harry to present his side.
Although Harry has been protected from Voldemort since infancy by spells Dumbledore cast that reinforce the protection created by the death of his mother's death, Dumbledorehe has taken additional precautions to ensure hisHarry's safety. Arabella Figg, a squib, has apparently been keeping a close eye on Harry since he came to live with the Durseleys. She explains that she has been rather mean to him because she knows if his aunt and uncle thinks he has a friend, they would not have allowed her to occasionally watch him. No doubt there are others who have also been watching Harry when he stays with the Dursleys.
