It's almost the winter holiday end of term. Hogwarts is all snowy and cold, especially the dungeons, and the students are all ready for a little break.
During Potions class, Malfoy makes fun of Harry and the people who can't go home for the holidays, since making fun of Harry during the Quidditch game hasn't worked out so well for him.
Harry is staying at Hogwarts over the holiday. The Weasleys are staying too, because their parents are traveling. Harry thinks it will be way better than going to the Dursleys'.
After Potions, Harry and Ron run into Hagrid, who's bringing a huge Christmas tree inside Hogwarts. Malfoy comes up behind them and makes fun of Ron's family for being poor.
Just when Ron attacks Malfoy, Snape appears and sides with his Slytherin student, even though Hagrid tries to stand up for Ron.
Ron and Harry talk about getting back at Malfoy. Hagrid distracts them by taking them to the Great Hall to look at the Christmas decorations. The Hall looks awesome.
Hermione is there and reminds them that they have to go to the library since they only have one day left before vacation.
When Hagrid asks why they're so gung-ho to study, they explain that they are trying to do research on Nicolas Flamel. Hagrid won't tell them anything else, and even though they've done a lot of research, they haven't dug anything up yet. They've checked many of the major books and come up with nothing.
Harry checks the restricted section, which has books about dark magic, but gets shooed out by the librarian. Ron and Hermione follow, and they confirm that no news has been found yet. Hermione asks them to keep researching while she's gone over the holidays.
When classes are over, Ron and Harry are stoked to have alone time to relax in. Ron tells Harry about wizard chess, where the pieces can talk and help (or hinder) the players. Ron has a family set and Harry borrowed one from Seamus.
Christmas Day, Harry is surprised and pleased to see that he got presents, just like Ron. He gets a flute from Hagrid, 50 pence from the Dursleys, a sweater from Mrs. Weasley, and Chocolate Frogs from Hermione. The coolest gift, though, is what Ron tells him is an invisibility cloak.
The cloak comes with an unsigned note that says the cloak belonged to Harry's dad.
Ron is jealous, and Harry is blown away.
Fred, George, and Percy come in, with Weasley sweaters, and go downstairs for the great feast.
The dinner is the best one Harry's ever had, with magic wizard crackers and all kinds of desserts. Harry gets even more presents from the crackers, including his own wizard chess stuff. He has a great rest of the day, with a Weasley snowball fight and more hanging out and eating.
When he goes to bed that night, he re-focuses on the puzzle of the invisibility cloak. He realizes the cloak will help him break a lot of rules. It's really amazing to have something that belonged to his dad, so he wants to try it out right away. He wants to use it by himself.
He slips out of the Gryffindor dorm and heads back to the restricted section of the library. He's sort of weirded out by how he looks when he's invisible.
In the library, the books look creepy and unhelpful. He picks one to look at but when he opens it, it starts screaming. Even though he quickly closes the book and tries to run away, the screaming continues. Filch comes in, looking for the intruder, as Harry runs out.
Harry finds himself in a corridor he doesn't recognize, next to some armor. He hears the voices of Snape and Filch, and he gets worried that he'll get caught. He goes into a room that he sees left open, and the other men don't seem to realize it when he moves away.
They leave, and Harry looks around the room. It has desks, chairs, and a tremendous golden mirror with strange words carved on the top. The words are "Erised stra ehru oyt ube cafru oyt on wohsi" (12.118).
Harry looks at the mirror, planning to geek out some more about being invisible, but freaks when he sees his reflection, and the reflections of a bunch of other people. He's not sure if there are other invisible folks in the room or what. When he looks in the mirror again, he sees a beautiful lady and a man, both of whom look a lot like Harry. He calls them "Mom" and "Dad," and realizes that the other people in the picture must be his relations.
He looks and looks in the mirror and is both really happy and really sad. He has a hard time leaving the people in the mirror.
The next morning, Harry gets Ron, because he wants to show him his family. He thinks Ron will be able to see his family too. Ron's not excited about that, and tries to get Harry to eat. But all Harry can think about is seeing his family again.
That night, Harry is worried they won't be able to get back to the room with the mirror, but they find it at last. When they go over to it, Harry sees his parents right away, but Ron can't. When Ron looks in the mirror by himself, he sees something very different: himself as head boy, Quidditch captain, and winner of the house and Quidditch cups.
They can't decide how the mirror works, and are in the midst of an argument when they're interrupted by the noise of Filch's cat. They decide to return to the dorm.
The next day, even though Ron tries to distract him, all Harry can think about is the mirror. Even though Ron thinks Harry shouldn't go back, it's all he wants to do.
That night, Harry ditches Ron and goes back to the mirror. He just sits and looks at his family.
Suddenly, he realizes that Dumbledore is there. Dumbledore explains to him how the mirror works: it shows the viewer his or her most inner desire. He explains Harry saw his family because he lost them, while Ron sees himself with all the attention, because he doesn't get it. Dumbledore says the mirror is really dangerous. He's going to take it away from Hogwarts and asks Harry not to follow it.
As they're leaving, Harry asks Dumbledore about what he sees in the mirror. Dumbledore says nice, warm socks. Later, Harry realizes that this might not have been his real answer.