Upstairs, Harry overhears Molly Weasley sobbing, and rushes in to see her attempting to fight a [boggart] - except it's alternately taking the form of all of her family members, dead. Lupin, Sirius, and Moody soon arrive and Lupin does off the boggart before comforting Molly, telling her how much better prepared the Order of the Phoenix is for Voldemort this time around.
Chapter 10 - "Luna Lovegood" - In which Harry and the Weasleys are late for the Hogwarts Express (again), Harry and Ginny encounter Neville on the train, and they are introduced to Luna Lovegood and her father's magazine, The Quibbler. Cho Chang makes a brief appearance, and Harry sees what actually pulls the school carriages.
All night Harry has bizarre dreams, of his parents, of the day's events, and of a corridor with a locked door.
Ron wakes Harry up and together they rush to make it out the door in time to catch the Hogwarts Express. Sirius comes along disguised as a dog as a rather large group walks to [Kings Cross Station], and they all just make it on the train before it departs.
Harry Meets Luna Lovegood
Harry, Ginny, and Neville settle into a compartment with Luna Lovegood, who Harry finds odd but somewhat entertaining. As the train moves along, Neville shows off his [Mimbulus mimbletonia] and douses everyone in [Stinksap], Cho Chang stops by to say hello to Harry, and the trio generally enjoys the trip.
Ron and Hermione arrive, talking about the new [prefects], but Luna soon joins the conversation, perplexing everyone else. Harry then reads her [Quibbler] with some interest, though Hermione quickly offends Luna with her insensitive comments about the magazine, which [Mr. Lovegood] publishes.
Malfoy Recognized Sirius