Chapter 21 of Harry Potter and the Half-Blood Prince: The Unknowable Room
Harry spends much spare time devising a way to retrieve Professor Slughorn's memory. As his potions book has been so useful, Harry studies it carefully. But Hermione points out that Slughorn will likely be protected against anything in the textbook. Harry notices a new curse in it, Sectumsempra, that is labeled, "For Enemies." He wants to test it, but knowing Hermione's objections to using the Prince's spells, he refrains. When Ron's Spell-Checking quill stops working, Hermione offers to correct the spelling on his essay. Ron jokingly responds that he loves her, causing a blushing Hermione to warn not to let Lavender hear him say that. Ron thinks maybe he should; he has been trying to dump her.
Kreacher and Dobby report to Harry regarding Malfoy's activities. Draco has spent considerable time inside the Room of Requirement. A "variety" of students stand watch while Draco is inside. Harry surmises these "students" are Crabbe and Goyle disguised by Polyjuice Potion stolen from Slughorn. He also guesses that the Room was not on the Marauder's Map because the map's creators never knew it existed, though Hermione suggests the room may be "unplottable" if the user needs it to be. Harry thinks he should be able to enter the Room of Requirement, just as Malfoy had when Dumbledore's Army was there. But Hermione counters that Draco knew what the Room was being used for.
The next day, Harry attempts to enter the Room of Requirement, but is unable to make the door appear. Later, in Defence Against the Dark Arts class, Seamus Finnigan asks about the difference between Ghosts and Inferi; Professor Snape says that a story in the Daily Prophet was actually was about Mundungus Fletcher, who was arrested for impersonating an Inferius. After class, Ron and Harry duck into a bathroom so Ron can avoid Lavender. There they find Moaning Myrtle, who says she was expecting someone else — a boy who has been crying.
Ron decides to take the extra Apparition classes being offered in Hogsmeade village. Hermione, meanwhile, repeatedly urges Harry to try and get Slughorn's memory. Harry is trying, but Slughorn, knowing what Harry is after, avoids being alone with him. Harry spends another day looking for Malfoy in the Room of Requirement. Tonks suddenly appears, claiming she is there to see Dumbledore, though Harry notices she is teary eyed. Harry relates this to Hermione, suggesting Tonks was in love with Sirius. Her Patronus' changed shape could reflect Sirius' Animagus dog form. Hermione thinks it is possible, but is doubtful.
Harry learns that Malfoy has been spending time in the Room of Requirement, which is why he periodically disappears from the Marauder's Map. However, Harry still has no idea what Malfoy is doing, and anyone he tells seems unconcerned. Harry only becomes more obsessed with following Draco, which could cause Harry to neglect Dumbledore's task to retrieve Slughorn's memory. Here, Harry does seem to be trying to handle both, along with his schoolwork, but he is becoming increasingly distracted by Malfoy's suspicious activities.
Harry is having significant difficulty entering the Room of Requirement. As we have seen, the Room can be anything that is required, but apparently it can be only one thing at a time; for instance, it can be a room full of chamber pots, as Dumbledore apparently discovered, it can be a place for a House-elf to sleep off a Butterbeer binge, as Dobby and Winky have done, and it can provide a space for Dumbledore's Army to practice Defence Against the Dark Arts. But once the room is occupied, in order to gain entrance, you must have that same specific need. Hermione is likely correct that Harry will be unable to enter until he knows what Draco needs, and, at least in this chapter, he is unsuccessful.
Ron may believe he is only joking when he tells Hermione he loves her, but he may actually be revealing his strong feelings for her, though he hardly realizes what those feelings are. And while he remains confused about what he actually feels for Hermione, there is no doubt about his feelings for Lavender—he wants to be rid of her.
Tonks' ongoing depression remains a mystery, but it has deeply affected her, to the extent that her Patronus has changed its shape. Harry believes she was in love with Sirius, while Hermione doubts this. One thing seems obvious, Tonks is secretly guarding Harry, twice now appearing just as he lands himself in trouble.
It may be interesting to note the difference in just how Kreacher and Dobby relay their report to Harry. Though Harry is nominally Kreacher's master, Kreacher begins his account with abuse and insults for Harry and compliments for Draco. Dobby cuts him off to tell Harry what he actually wants to know. Kreacher's behavior seems almost childish, and so seems accurate for what we know of House-elf character in general.
Readers should perhaps wonder why a boy would be crying in Moaning Myrtle's lavatory and why Myrtle seems to be expecting him.
Inferi are mentioned, though not for the first time, but it is only now that they are defined. We should take note, as the author is generally efficient, and they will likely be mentioned again. We also may suspect that the Sectumsempra spell, which is at least a jinx, and more likely a curse, will also reappear.
- Why does Harry decide not to test the Prince's Sectumsempra spell?
- Why does Harry believe his Potions book can help him retrieve Slughorn's memory? What does Hermione say?
- Why does Tonks say she is looking for Dumbledore? What does she mean by "nothing in particular"?
- Why is Tonks always so sad? Why does Hermione doubt that Tonks was in love with Sirius?
- What might Draco be doing in the Room of Requirement?
- Ron jokingly tells Hermione he "loves" her. Is he really joking or do his words reveal deeper feelings? What is Hermione's reaction?
- Who might the sobbing boy in Moaning Myrtle's bathroom be and why does he go to that particular place? Why would he be crying?
It is perhaps surprising that the Room of Requirement can be used to carry out what we assume is a task for Voldemort, as Hogwarts is supposed to be protected from Dark Magic. There are several possibilities here. One possibility is that the Room of Requirement is an exception, or that someone has performed a spell which allows it. Another possibility is that what is being done is not Dark as such, but can be used for Dark purposes. What Draco is doing is repairing a Vanishing cabinet, a task which in isolation is not Dark. It is the use it is put to once it is repaired that makes it so useful to the Dark side.
Draco, meanwhile, is becoming increasingly distraught over the task he must perform for the Dark Lord and the real danger his family is in should he fail. He eventually seeks solace from Moaning Myrtle, frequently sobbing to her in the lavatory.
When Voldemort found the Room of Requirement, he was apparently looking for someplace to hide something, likely the result of some Dark experiment gone awry. Thus, when he told Draco how to open the Room of Requirement, he shared only what he knew about the room, its "hiding place" form. Harry would be able to open the Room while Draco occupied it if he told it that he needed a place to hide something, that being the way that Voldemort and Draco were opening it; but Harry, knowing that the Room could be anything, persists in asking it to be a place where he can work on something. This is, strangely perhaps, a case where Harry has too much understanding for the task at hand.
Harry's decision to heed Hermione's advice and refrain from testing the Prince's spells on someone without knowing the results was a wise one. Sectumsempra has a devastating effect, which, had it been used in a different circumstance, could have cost someone their life, and in a later chapter, it will be nearly fatal for someone. It is somewhat curious that Harry never guesses its purpose from the incantation; we have seen that spell incantations are based on Latin, and this spell's incantation appears to be based on the Latin for "cut forever", a fair description of its action.
It is revealed later that Tonks is in love, not with Sirius, but with Remus Lupin. While Lupin also cares for Tonks, he has rejected her feelings because he believes he is too old for her, is generally concerned about bringing children into the current world, and about them having a Werewolf father in particular. Not wanting to risk passing on his affliction to his offspring, Lupin refused to marry Tonks. Note that this being a book intended for children, it is assumed that there is no extramarital sex, so Lupin and Tonks must get married as the next stage in their relationship, and marriage implies children.