"Maybe we should just go up on the roof," Ron complained.
They'd spent all morning Saturday wandering around the unmapped space on the seventh floor pushing bricks, trying to tilt torch sconces, looking for hidden runes, and casting what detection spells they knew. A hidden door had yet to make itself known, and they were all getting kind of sick of being looked at by Barnabus the Barmy from his tapestry where he was trying to teach trolls to tapdance.
Hermione disagreed, "I think it's more likely that this is something Rowena Ravenclaw or Godric Gryffindor hid here, just as Salazar Slytherin hid the Chamber."
"So we may not even be able to get in if we can't give a password in some magic only they had?" Harry figured.
"Maybe…" she admitted, not liking how accurate that limitation would be if her theory was correct. "Well, if so, then this has been very pointless and I think we should spend the time doing research."
The twins and Lee had already given up, having already devoted quite some time trying to figure out the empty space in previous years when they'd noticed the hole on the map. Lee was off making time with his girlfriend, and Fred and George were leaving obvious contraband in all of their other secret places in the school to try to evaluate which ones Filch knew about and would clean out.
"Go ahead," Harry allowed. "I think I'm going to keep at it a little longer, and see you both at lunch. What do you think, Padfoot, go with them or stay with me?"
Sirius huffed and shouldered Harry from his "Padfoot" dog form, conveying efficiently that he hadn't sneaked into Hogwarts to just let Harry be in danger on his own.
"Okay, be careful, both of you," Hermione agreed, before she and Ron headed off to research jinxes.
Harry probably spent another half hour using his inspect ability on random fixtures around the hallway, getting strange looks from the occasional passing Ravenclaw or Gryffindor, while Sirius snuffled around.
Sirius Black replies: I'm worried Ron is right. I don't smell any places where anyone's scent disappears into the wall.
"Maybe it's just that nobody's found it recently," Harry told him, quietly, rather than using the game system to talk. "Which is what we want. A room nobody else goes into."
Sirius Black replies: Fair. And there's got to be something in there. They wouldn't have just made a solid block on the top floor.
Reply to Sirius Black: Careful, Dumbledore incoming.
"Ah, Harry," Dumbledore said, rounding the corner from where Harry had seen his dot traveling on the map. "Getting Remus' dog some exercise?" He didn't seem to have any clue that Sirius was anything more than a dog, who had moved to sit patiently next to Harry rather than roaming on his own.
"Well, he's laid up today so can't take him for a walk?" Harry ventured.
"You're aware of his condition, I take it?" the headmaster worked out, strolling to a stop a couple of yards from Harry and Sirius.
"Yes, sir," he agreed. "But we're trying to keep it quiet."
Dumbledore's eye flickered almost imperceptibly at the "we" in that statement, working out that all of Harry's friends must know and filing that away. Instead of commenting on it, however, he said, "An interesting corridor for it. One of the great secrets of the school, what lies on the other side of that wall."
"Is it, sir?" Harry checked, wondering if the old man was trying to give him a hint or just pointing out that he realized what Harry must be investigating. "We thought it might just be your private bathroom, or something."
"Alas, nothing so grand. Though, should you make prefect, such a wonder does await elsewhere in these halls." Harry tried not to show that he was already well aware of the super-nice bathroom for prefects on the fifth floor and had the password should he need to use it. "But no, I like to leave myself a few mysteries, and couldn't possibly speculate on what might be on the other side of this wall."
Sirius Black replies: He didn't actually say he doesn't know.
"Who do you think could speculate, sir?" Harry asked, realizing that Sirius was right.
"Well, if anyone knows more than I do about this school, it would have to be its custodial staff…" the old man mused, as if absently recalling the information.
Sirius Black replies: The elves! Why didn't we think to ask the elves?!
"Thank you, sir," Harry nodded. "Maybe they'll have some ideas on how to help Dobby, too."
"I'm happy to hear you still have the well-being of that young elf in mind," the headmaster agreed. "Padfoot there looks excited by the trip, as well," he mentioned, catching Sirius' emotion at the realization about the school's house elves. "Don't get so wrapped up in your explorations that you forget lunch."
"I'll drop Padfoot off with Remu… er… Professor Lupin and be right down," Harry agreed. As soon as Dumbledore nodded and headed out, he messaged the group:
[Marauders] Harry Potter: Dumbledore probably knows what's in there. But he suggested we ask the house elves. I'm bringing Sirius back to Remus' office and heading to lunch.
Fred and George, who'd visited before, suggested they actually wait for an hour to give the elves time to clean after lunch, then led them down to the kitchens. Harry's game map inherited the text prompting him with the entry method from the Marauders' Map: tickling the pear on a large painting that guarded the entrance. Within, the enormous kitchen was a bustle of activity as dozens of tiny creatures much like Dobby finished cleaning the last of the lunch dishes while starting on their dinner prep.
There was a general pause as the elves spotted the seven students entering their domain, a moment of recognition of the twins, and then a hushed gasp as they realized that Harry was with them.
OLVIE
House Elf, Level 15
The elf that approached in her clean Hogwarts-branded towel-toga wasn't quite as old as Kreacher, but was clearly the matron of the kitchens. "Harry Potter, sir. Can we be getting you and your friends a snack?"
"No, but thank you, Ms. Olvie," he said, and it obviously rippled through the crowd that the Boy-Who-Lived knew her name, and said it with such respect. "We don't mean to intrude, but we had a couple of questions that you might be able to answer?"
"Olvie is happy to help!" she agreed, gesturing them to step further into the kitchen and then motioning the other elves to get back to work. "Ask your questions."
"There's a space up on the seventh floor that we can't get into. We were wondering if you knew what was in there and how to get in?" he led off.
"Harry Potter means the Come-and-Go Room," she nodded, with only a moment's hesitation about revealing it. "Elves use it to store spare items for the school."
"Oh! So you have to be able to teleport to get into it," Hermione realized. "It doesn't need a door." She was excited to have solved that mystery, but a little sad about the room being inaccessible.
"Apologies, miss, but it does have a door," Olvie corrected. "It just only appears when needed. There is a funny tapestry with trolls? You just walk up and down that hallway three times thinking about what kind of room you need, and the door appears."
"Wait, what kind of room we need?" Harry caught. "Does the room change somehow?"
She nodded, "Some wizards once called it the Room of Requirement."
"Brilliant," Harry grinned, and Olvie beamed having made him happy. "Okay, umm, another question. Do you know the elf, Dobby? His family is the Malfoys." Harry wasn't sure whether it was weird to assume that all elves knew each other.
"I knows him from his mother, yes," Olvie agreed, smile failing and her mood turning a little guarded, not sure where Harry was going with his questions.
"Well," he rolled on, "it seems like the Malfoys mistreat him and I'm trying to figure out how to help him. Surely the geas," he was sure he almost pronounced it right, "can't be meant to force you to hurt yourselves?"
She nodded sadly, admitting, "It is not meant to, but some wizards are bad masters. Elves draw power from their bond with wizards through the geas. Our powers be fading without that bond."
"Isn't that just slavery!?" Hermione couldn't help but blurt out.
"Be a vassal a slave, miss?" Olvie asked. "Wizards are meant to provide power and protection for service."
"Oh… like a knight that runs a manor," she nodded, incorporating that into her worldview. "I think feudalism had a lot of problems, but I guess that's not as bad as slavery… but wouldn't you rather be free?"
"Free to scrabble for power and meaning?" the elf matron asked, not unkindly, though several elves working nearby had gasped in shock at the suggestion. "There are other fae that are free like that… you have some of them trapped in a cabinet for your defense classes, miss."
"Doxies!" she realized. "They get into magical houses because they need some of the power and they have no other way to get it! So… you get a share of your family's power?"
"Exactly, miss. It's a good life, if the family is good. If the family is bad…" Olvie turned back to Harry and said, "Master may give clothes to show the oath is abandoned, and does not necessarily need to mean to…" He nodded at that, having had a similar idea of maybe tricking Malfoy into giving Dobby a piece of clothing. "A geas may also be claimed by a superior wizard, should the master be defeated and the elf wish to change households."
"You can just duel Lucius Malfoy," George grinned.
"No pressure," Fred quipped.
"I don't suppose I could just beat Draco?" Harry asked.
Olvie shook her head, "It must be head of family."
"Okay," Harry sighed, thinking that tricking Lucius somehow was probably still easier, "thanks so much. We'll let you get back to work. Thanks for all the help!"
"Come back any time, Harry Potter. And friends," she waved them out.
"Not going to go through with SPEW after all?" Ron asked Hermione, as they were making their way back up to the seventh floor.
"I still might!" she argued. "It just needs more nuance, I guess. Those elves seem happier than Dobby and Kreacher, at least. Maybe we basically just need an elf Magna Carta, outlining more rights…"
"What's SPEW?" Harry asked, since she didn't seem to want to elaborate.
"Society for promotion of elvish welfare," she answered, absently, still thinking through the new revelations.
"She was planning on making badges. Trying to get everyone to free their elves," Ron elaborated. He'd clearly been trying to talk her out of it.
"They do need protecting, in some families," Harry agreed, visions of stuffed elf heads lining the stairs in Grimmauld Place filling his head. "Hey. I wonder if Kreacher can't clean because he barely has a master anymore. Maybe if Sirius worked harder, he'd get more powerful?"
"Be the change you want to see in the world," Hermione nodded. "He should be nicer to that elf… even if he is extremely rude and racist."
The corridor was clear when they got back up to the tapestry of the dancing trolls, and Harry announced, "Okay, everyone hang back for a moment. Three times?" He began to walk down the length of the tapestry and back saying, "I need a place to brew potions. I need a place to brew potions. I need a place to brew potions."
As he finished his third trip, the Surplus to Requirements quest completed, a door appeared, and the Marauders stepped forward to check out what they'd managed to discover…