 Just as Harry is starting to anticipate his return to Hogwarts School , an impish house @-@ elf named Dobby arrives out of nowhere to warn Harry against the decision to return to the wizarding world , citing grave danger as the reason and inciting Harry ’ s gravest punishment yet when he smashes a dessert crafted by Petunia for the dinner party and frames it on Harry himself . Ron Weasley arrives with his twin brothers Fred and George to perform a jailbreak in their father Arthur ’ s enchanted Ford Anglia and to deposit him at their family home the Burrow for the remainder of his holidays . Harry and the rest of the <unk> Molly , third eldest son Percy , and daughter <unk> to Diagon Alley , where they are reunited with Hermione Granger and introduced to Lucius Malfoy , father of Harry ’ s school nemesis Draco , and Gilderoy Lockhart , a conceited autobiographer who has been appointed Defense Against the Dark Arts professor . As Harry and Ron plan to depart with the rest for Hogwarts School , the barrier within King ’ s Cross station that separates Muggles from wizards refuses to allow them passage , forcing them to fly Arthur ’ s car to the school , where they crash into a sentient willow tree on the grounds . 
