“Yeah, I know that, thanks,” said Harry, not looking up from the book. “That’s why I’m looking for something different. Dumbledore says Veritaserum won’t do it, but there might be something else, a potion or a spell…”
“You’re going about it the wrong way,” said Hermione. “Only you can get the memory, Dumbledore says. That must mean you can persuade Slughorn where other people can’t. It’s not a question of slipping him a potion, anyone could do that—”
“How do you spell ‘belligerent’?” said Ron, shaking his quill very hard while staring at his parchment. “It can’t be B—U—M—”
“No, it isn’t,” said Hermione, pulling Ron’s essay toward her. “And ‘augury’ doesn’t begin O—R—G either. What kind of quill are you using?”
“It’s one of Fred and George’s Spell-Check ones, but I think the charm must be wearing off.”
“Yes, it must,” said Hermione, pointing at the title of his essay, “because we were asked how we’d deal with dementors, not ‘Dugbogs’, and I don’t remember you changing your name to ‘Roonil Wazlib’ either.”
“Ah no!” said Ron, staring horror-struck at the parchment. “Don’t say I’ll have to write the whole thing out again!”
“It’s okay, we can fix it,” said Hermione, pulling the essay toward her and taking out her wand.
“I love you, Hermione,” said Ron, sinking back in his chair, rubbing his eyes wearily.
Hermione turned faintly pink, but merely said, “Don’t let Lavender hear you saying that.”
“I won’t,” said Ron into his hands. “Or maybe I will, then she’ll ditch me.”
“Why don’t you ditch her if you want to finish it?” asked Harry.
“You haven’t ever chucked anyone, have you?” said Ron. “You and Cho just—”
“Sort of fell apart, yeah,” said Harry.
“Wish that would happen with me and Lavender,” said Ron gloomily, watching Hermione silently tapping each of his misspelled words with the end of her wand, so that they corrected themselves on the page. “But the more I hint I want to finish it, the tighter she holds on. It’s like going out with the giant squid.”
“There,” said Hermione, some twenty minutes later, handing back Ron’s essay.
“Thanks a million,” said Ron. “Can I borrow your quill for the conclusion?”
Harry, who had found nothing useful in the Half-Blood Prince’s notes so far, looked around; the three of them were now the only ones left in the common room, Seamus having just gone up to bed cursing Snape and his essay. The only sounds were the crackling of the fire and Ron scratching out one last paragraph on dementors using Hermione’s quill. Harry had just closed the Half-Blood Prince’s book, yawning, when—
Crack!
Hermione let out a little shriek; Ron spilled ink all over his freshly completed essay, and Harry said, “Kreacher!”
The house-elf bowed low and addressed his own gnarled toes. “Master said he wanted regular reports on what the Malfoy boy is doing, so Kreacher has come to give—”
Crack!
Dobby appeared alongside Kreacher, his tea-cozy hat askew. “Dobby has been helping too, Harry Potter!” he squeaked, casting Kreacher a resentful look. “And Kreacher ought to tell Dobby when he is coming to see Harry Potter so they can make their reports together!”
“What is this?” asked Hermione, still looking shocked by these sudden appearances. “What’s going on, Harry?”
Harry hesitated before answering, because he had not told Hermione about setting Kreacher and Dobby to tail Malfoy; house-elves were always such a touchy subject with her.
“Well… they’ve been following Malfoy for me,” he said.
“Night and day,” croaked Kreacher.
“Dobby has not slept for a week, Harry Potter!” said Dobby proudly, swaying where he stood.
Hermione looked indignant.
“You haven’t slept, Dobby? But surely, Harry, you didn’t tell him not to—”
“No, of course I didn’t,” said Harry quickly. “Dobby, you can sleep, all right? But has either of you found out anything?” he hastened to ask, before Hermione could intervene again.
“Master Malfoy moves with a nobility that befits his pure blood,” croaked Kreacher at once. “His features recall the fine bones of my mistress and his manners are those of—”
“Draco Malfoy is a bad boy!” squeaked Dobby angrily. “A bad boy who—who—”
He shuddered from the tassel of his tea cozy to the toes of his socks and then ran at the fire, as though about to dive into it. Harry, to whom this was not entirely unexpected, caught him around the middle and held him fast. For a few seconds Dobby struggled, then went limp.
“Thank you, Harry Potter,” he panted. “Dobby still finds it difficult to speak ill of his old masters.”
Harry released him; Dobby straightened his tea cozy and said defiantly to Kreacher, “But Kreacher should know that Draco Malfoy is not a good master to a house-elf!”
“Yeah, we don’t need to hear about you being in love with Malfoy,” Harry told Kreacher. “Let’s fast forward to where he’s actually been going.”
Kreacher bowed again, looking furious, and then said, “Master Malfoy eats in the Great Hall, he sleeps in a dormitory in the dungeons, he attends his classes in a variety of—”
“Dobby, you tell me,” said Harry, cutting across Kreacher. “Has he been going anywhere he shouldn’t have?”
“Harry Potter, sir,” squeaked Dobby, his great orblike eyes shining in the firelight, “the Malfoy boy is breaking no rules that Dobby can discover, but he is still keen to avoid detection. He has been making regular visits to the seventh floor with a variety of other students, who keep watch for him while he enters—”
“The Room of Requirement!” said Harry, smacking himself hard on the forehead with Advanced Potion-Making. Hermione and Ron stared at him. “That’s where he’s been sneaking off to! That’s where he’s doing… whatever he’s doing! And I bet that’s why he’s been disappearing off the map—come to think of it, I’ve never seen the Room of Requirement on there!”
“Maybe the Marauders never knew the room was there,” said Ron.
“I think it’ll be part of the magic of the room,” said Hermione. “If you need it to be unplottable, it will be.”
“Dobby, have you managed to get in to have a look at what Malfoy’s doing?” said Harry eagerly.
“No, Harry Potter, that is impossible,” said Dobby.
“No, it’s not,” said Harry at once. “Malfoy got into our headquarters there last year, so I’ll be able to get in and spy on him, no problem.”
“But I don’t think you will, Harry,” said Hermione slowly. “Malfoy already knew exactly how we were using the room, didn’t he, because that stupid Marietta had blabbed. He needed the room to become the headquarters of the D.A., so it did. But you don’t know what the room becomes when Malfoy goes in there, so you don’t know what to ask it to transform into.”
“There’ll be a way around that,” said Harry dismissively. “You’ve done brilliantly, Dobby.”
“Kreacher’s done well too,” said Hermione kindly; but far from looking grateful, Kreacher averted his huge, bloodshot eyes and croaked at the ceiling, “The Mudblood is speaking to Kreacher, Kreacher will pretend he cannot hear—”
“Get out of it,” Harry snapped at him, and Kreacher made one last deep bow and Disapparated. “You’d better go and get some sleep too, Dobby.”
“Thank you, Harry Potter, sir!” squeaked Dobby happily, and he too vanished.
“How good is this?” said Harry enthusiastically, turning to Ron and Hermione the moment the room was elf-free again. “We know where Malfoy’s going! We’ve got him cornered now!”