Nobody could talk Hermione out of putting both her level-up perks into Willpower. It wasn't just hoping to get Mental Fortress (not that they had any way to test it, and suspected she probably hadn't started at 14 so would need at least one more perk invested anyway). She was also enamored with the additional magical stamina. She had a grand plan to start working on Perception once she couldn't raise Willpower any further, for the full mental package.
Ron was about to split his perks between Body and Charisma again, before realizing that he didn't have the clothing for another major growth spurt. He'd have to hope to gain another level by the next summer, unless he was willing to sit on the perk until maybe Christmas. Bemoaning the inefficiency of not specializing the team, he decided to raise Intelligence and Charisma instead. He was grudgingly realizing that, even if he never planned to be as smart as Hermione, it would probably help him with tactics and with keeping up with his schoolwork.
They assumed that was how it worked, at least. It wasn't like Hermione had gotten nearly half again as efficient at her essays like the 14 to 20 jump would imply. But maybe at 14 she was already so close to "the best you could do on schoolwork assigned to 12-year-olds" that it was hard to notice the difference. Ron at least seemed to think that it was a little easier to remember concepts from class, after taking the perk.
Also, with his Charisma presumably now somewhere in the mid-teens, he was finding it even easier to persuade Percy to donate his valuable time to help him with concepts he didn't understand. He'd tried to get extra help from Hermione, but her enhanced Willpower seemed more than a match for his enhanced Charisma, at least when it came to talking her into writing his essays for him.
She was finding it hard not to look at him when she thought he wouldn't notice, though.
After rescuing Hagrid, life had proceeded to roll on without any new major excitement other than the most recent night of Harry's strange dreams. They had confirmed with Remus and Sirius that they were in Germany trying to find Pettigrew, and several of the Slytherins had gotten mail they didn't seem to be expecting at breakfast that morning, from what were probably school owls rather than their fancy family familiars.
While Harry was hazy on exactly why he associated the Heir with a room made of paper—figuring that part was some kind of dream logic—he did remember them commenting on maybe killing Hedwig, and had taken to keeping her in his personal menagerie when he wasn't contriving postal errands. She seemed very interested in the task of taking mail to Remus and Sirius in Europe. If nothing else, it would be good cover for their information from the werewolf.
Unfortunately, they couldn't exactly just go over and read the letters the Slytherin kids had gotten. But Fred and George suggested that they'd handle it. All they asked was a loan of Harry's invisibility cloak once they put their plan into motion.
And Saturday two weeks before Halloween was when they managed to accomplish it, taking advantage of the Hogsmeade weekend for upper-years. "None of you appreciate how much I do for this organization," Lee complained when they gathered up in a secret passage before dinnertime.
"What did you do?" Ron checked.
"Chatted up Nerys Orpington. All afternoon," he shuddered. "First to make sure she didn't have the letter with her, and then to distract her and her roommates while these blighters snooped."
"How were you sure she didn't have it on her?" Ron asked, fascinated.
"I'll tell you when you're older," he patted the younger boy on the head.
Before Ron could clap back, Fred said, "Their room is a mess, by the way."
"Definitely the least tidy girls' dormitory we've been into," George agreed.
"Don't the Slytherins have the same charm to keep boys out that our dorms have?" Hermione checked, worried that the twins were implying that they could get into her room if they wanted to. She'd been assuming her bed was safe from their pranks.
"Purity charms last updated by the actual Puritans are no match for modern ingenuity," George shrugged.
"And the Slytherin dorm doesn't have staircases to turn into a slide, so it's easier," Fred added.
"The trick for our dorms is the walls," George told the younger boys in a stage whisper.
"Can't slide down if you're not touching the steps," Fred nodded.
A bit horrified at the image of the boys bypassing the charm by simply chimneying their way up, Hermione demanded, "But you got the letter?"
"Naturally," Fred agreed.
"We're very secret-agent-of-the-queen," George displayed the document.
Folded up, it was exactly the size and shape Harry remembered from his dream. When unfolded, it was a single page of text. Lee went ahead and read it aloud rather than waiting on different reading speeds in the dimly-lit hallway.
Mistress Orpington,
I represent someone who thought very highly of your grandfather, Rhys Orpington, and vouchsafes that they had traded favors on many occasions. The time has come to renew some of these old friendships. As is the way of Slytherin, favors will be given for favors done, and my patron has a wide array of capabilities, as do I.
There is an illusory brick beneath the third sink in the third floor girls' loo. If you are interested in a demonstration, please leave a short list of tasks you are unable to conclude yourself, either due to capability or deniability, and your wishes will be granted. Return to the same location for further communication, once our power has been proven.
In hopes of a mutually-beneficial correspondence,
A Friend of Your Family
They took that in for a moment, then Harry asked, "They're offering to kill somebody right? That sounds like offering to kill somebody."
"They definitely want it to sound like it's on the table," George agreed.
"Bet they'll waste their 'wishes' on something simple, like a prank, though," Fred added, then glanced at his brother.
"We could grant wishes," they said simultaneously.
"Alright Robin and William," Hermione said dismissively. She then had to lamely explain, "There's a new cartoon coming out soon about a genie that grants wishes. He's played by Robin Williams. So I called you…"
"Got it," Fred nodded, kindly.
"We need to tell you some more wizarding stories so we'll get your zingers without you having to explain them," George helped.
"Anyway," Harry pulled them back on track, "so we just check the hidden brick in the loo?"
"I bet that hole's there because of our fight with the troll!" Ron realized.
"If they're smart, they would have given a different dead drop to everyone," Hermione reasoned. "Especially since the notes went to mostly boys, who would be suspicious in the girls' toilets. Wait… if the Heir is a boy, that would be obvious!"
"It's not that hard to sneak into the girls' loo," Fred shrugged.
"But, yes, it could be a girl," George agreed, before Hermione lost her mind as all the spaces she'd thought she was safe from the twins were rendered suspect.
"And we don't know if Orpington already left a letter," Ron suggested. "The Heir might have suggested a different place after the first letter, and we'd never find it."
Lee said, "I haven't heard any rumors of suspicious things happening that benefit the Slytherins. The Heir may be waiting until everyone gets their requests in before doing any of them. And since like half the Slytherin quidditch team got a letter, I bet they ask for help cheating at the match in three weeks."
Harry nodded, "So we basically have to figure out how to catch someone that can go check that spot at any time, and might leave a letter anytime in the next three weeks. Oh, and stop them from killing us all out on the pitch." He rolled his eyes, "I don't fancy getting jinxed off my broom again."
"At least we know what to look for now, rather than just jumping to lighting Snape on fire out of principle," Ron grinned.
"It was bluebell flames," Hermione argued. "He'd have been fine, regardless. But, yes, we need to prevent the Heir from helping the Slytherins cheat at the match. If only to deny her more helpers for completing the 'wish' she was asked for."
"Ooh, we're going with 'her' are we?" Fred joked.
"Our Hermione is feeling the need for a lady villain to match wits against," George grinned.
"Well…" she said, "...I really could do with another girl in this boys' club. I guess a female nemesis is the closest I'm going to get."
"We could read in Gin," Fred suggested.
"I think she knows something's up anyway," George agreed.
"Have to pry her out of that diary first," Ron shook his head. "And I don't think we can get her to promise she wouldn't tell mum if she got mad at us."
"Fair," Fred allowed.
"We'll need to get enough blackmail on her first that it will be mutually-assured destruction," George calculated.
"Anyway," Hermione was the one to return from the tangent this time, "how do we catch the Heir? Some kind of constant surveillance on that loo to see who goes for the brick? Assuming Nerys didn't already leave her letter."
Ron suggested, "Hermione, why don't you go see if Nerys' letter is already there? Would make this a lot easier if she left her letter but the Heir hasn't grabbed it yet."
"Right!" she gave him a brilliant grin at the suggestion. "Back in a minute." She slid out of the passage in the direction of the third floor. It only took about three minutes for her to return, since the bathroom wasn't far from the secret passage, and she was triumphantly brandishing a letter. "It was there!"
"Perfect," George nodded. "You thinking what I'm thinking?" he asked Fred.
"If we can trust them to keep it a secret, indubitably," his brother agreed.
"We probably should have involved them anyway," George shrugged.
"Right. So, yes, this makes it very easy, since we already have a prank in mind," Fred explained. "But let's read the letter first."
"Make sure it's not already pranked," Ron suggested, well used to trying to read other people's' mail in the Weasley house and how that sometimes backfired.
The twins nodded and did some detection spells that Harry tried to memorize, before declaring it as safe as they could. Lee once again did the honors of reading Nerys' letter aloud.
Family Friend,
I find your missive intriguing, and am interested in pursuing a renewal of our family's connection. As requested, some issues that I find difficult to obtain through my own resources include being released from the detention I must serve with Filch during the next quidditch match, embarrassing Gloria Williams to the point that I am a more obvious choice for prefect next year, and obtaining a pass to the Restricted Section of the library for a whole weekend.
I look forward to a mutually-beneficial arrangement.
"Unsigned," Harry noticed. "Smart. If someone finds it, it gives her… Hermione, what's that term?"
"Plausible deniability?" Hermione suggested.
"Right," Harry agreed. "So what's this great prank?"
"Remember how you distracted mum for us at the Alley and helped us bring some packages home?" Fred began.
"We got a lot of Illustrious Irving's Invisible Ink," George continued. "You can spell it to become visible again at a certain time. And it comes in powder form."
"The plan is to dust everyone with it, set to become visible during the Halloween feast. And we got it in pumpkin colors," Fred elaborated.
"So we can just put some in the letter to spray the Heir. Maybe save the green for the letter and people we're sure aren't the Heir, so she doesn't even suspect. Will just think she was one of the random greens," George concluded.
"But we'll know that the person that turns green that we didn't put it on is the Heir," Harry said. "Brilliant."
"What if the Heir gets it on herself today?" Hermione checked. "Won't it wear off in two weeks?"
"Unlikely," Fred said. "Supposed to be pretty durable, especially when you don't know it's there yet."
"We were planning to gradually dust people over the next couple of weeks anyway, so people would be less likely to notice," George explained.
"Alright," Harry nodded. "So you put some of the green in the letter and Hermione puts it back. Then we just have to wait for the feast and keep an eye out. Easy enough."
HAPPY HOLI-WEEN
O Help Fred and George with their prank
O Find the Heir of Slytherin
"Should we have a backup plan?" Ron checked.
"Nah, I'm sure this one's foolproof," Fred grinned.
"And if it isn't, we'll still have a week between the feast and quidditch. No pressure," George nodded.
"Quest log thinks it will work," Harry shrugged. "I'm sure it'll be fine."
"Mate," Ron sighed. "You jinxed it."