A/N: Hi, everybody! It's been a while, I know. I'm sorry. Junior year hit me very hard with homework, and I hardly had any free time. And I was lazy this summer. Without further ado-

... or Amelia Bones or Rabastan Lestrange or Pomona Sprout or...

"Wait here," McGonagall instructed curtly. "The Headmaster will be here shortly."

With that, she slammed the door shut, rather loudly, Harry thought.

Phineas and Ferb turned to look at the office.

"Whoa!" Phineas said, rushing up to a tiny, silver instrument on a table. "Ferb, you gotta see this! I wonder what it does..."

"Phineas! This is the Headmaster's office!" Candace told them angrily, storming over to the table. "Don't touch anything. It could explode, or spontaneously combust - "

"We're not going to touch anything," Phineas said with a laugh. "I mean, that would be kind of dumb. We are going to do a few preliminary scans and attempt to reconstruct these later in the dorm."

As he said it, Ferb produced an absurdly large blueprint and a pen from his pocket.

While Phineas and Ferb continued to examine the many strange things in Dumbledore's office, Harry found himself wandering off alone. His head was spinning. How could he explain to Dumbledore that he was innocent? In his head, he tried to piece his story together. Professor, I swear, I was just wandering around the hallways when I happened upon Justin's Petrified body...

Wow. Even in his head it sounded incredibly lame.

Harry shoved his hands in his pockets and looked around the room, trying to get his mind off of his impending punishment. He wandered over to some shelves and started examining the contents. There were books, most of them incredibly old, along with other curious, whirring objects... and the Sorting Hat!

All the whispers and rumors floating around the school started popping up in his head again. Surely it wouldn't hurt to check? The Sorting Hat would never put Slytherin's heir in Gryffindor, right? Harry turned around and made sure Phineas and Ferb weren't looking. For some reason he felt guilty putting the hat on again, as if he were confirming his doubt. Phineas and Ferb were busy with some kind of moon globe across the room, so Harry reached up on his tiptoes and grabbed the hat from its pedestal. He put it over his head and waited patiently.

"Ah, Mister Potter! Well I remember your sorting."

"Can you tell me... ?" Harry began in a whisper.

"You're having doubts as to your House?"

Harry didn't respond. It was a magic telepathic hat, after all.

"Well, Potter, I stand by what I said at the sorting ceremony. You would have done well in Slytherin."

Harry felt a horrible sinking feeling inside of him. He tore the hat from his head and was about to put it back on the shelf when he heard Phineas behind him.

"Hey, Harry! Is that the Sorting Hat?"

"Er... yes..." Harry said, feeling kind of silly.

"Cool. Ferb and I just found a magical astronomy calculator that appears to operate on the duodecimal system. Can I try the hat on?"

Harry handed the Sorting Hat down to Phineas, who put it on, which is no small feat for one with a triangular head.

"Phineas Flynn?" the hat asked.

Phineas grinned. "In person."

"You don't appear to have any kind of mental or existential crisis going on."

"It's just a sort of check-up, I guess."

The hat laughed. "You should know that I had the hardest time sorting you, Phineas Flynn. In fact, I almost didn't sort you at all. I could tell right away that you were no wizard. But then I saw what an extraordinary mind you happen to possess. I didn't exactly sort you, anyways. I just put you in Ravenclaw to be with your stepbrother."

"Then, what House should I really be in?"

"I personally hold that you're more on the Gryffindor or Hufflepuff end of the spectrum. If I had to choose one House, I'd pick Hufflepuff. Family is the most important thing of all to you, and that's why I put you in with Ferb."

"Cool. Thanks."

Phineas took off the hat and smiled at the group around him.

"Well, that was certainly an interesting character study. Anybody else want to try? How about you, Candace?"

Candace crossed her arms. "I refuse to let that thing of weirdness anywhere near me."

It was at this moment that the cheery dialogue was interrupted by a dry croaking sound. Everybody turned around towards the source of the sound, which happened to be Dumbledore's desk. There was a scraggly, sickly bird perched on top of it, with dropping greyish feathers and dull eyes.

"What is that?" Candace asked.

Harry shrugged. "Whatever it is, it looks like it's dying. Wouldn't that be something? All of us here in Dumbledore's office when his pet snuffs it –"

At this precise moment, the bird burst into flames.

"See, Phineas, I told you this would happen!" Candace shrieked. "Look what you've done!"

Harry yelped, looking around the office for... well, he didn't really know. It was very unlikely that Dumbledore kept a glass of water out for occasions just like this.

"Do something!" Harry said to Phineas.

Phineas pointed his wand at the bird. "Aguamenti!"

A stream of water burst from his wand like it was a firefighter's hose. It hit the bird from the side, sending it crashing to the ground with a large poof of smoke. When the water stopped, there was a somewhat blackened, but otherwise unharmed bird sprawled on the floor.

Behind them, a door opened and shut.

"Ah, Harry. I apologize for making you wait."

"Professor, your bird, it just spontaneously combusted!" Harry yelled, turning around to face Dumbledore, who had just entered the room.

Dumbledore smiled. "Did he, now?"

"Don't worry, though," Phineas added. "We managed to put him out."

Dumbledore stopped smiling. "You... put him out?"

"Yeah," Phineas said. "Just kind of... poof! It was on fire! But a quick water spell did the trick."

Dumbledore ran off towards his desk and bent over the bird, waving his wand over the sodden mess.

"Although I truly appreciate your good intentions," Dumbledore told them, as the puddle on his floor shrank and vanished, "it was quite unnecessary. Fawkes is my pet phoenix. They are nearly immortal beings, who burst into flame when they die and are reborn from the ashes."

Dumbledore replaced Fawkes on his perch, and then sat down behind his desk. He pushed his classes further up his crooked nose.

"Now, Harry, I believe we need to discuss something."

"It wasn't me, Professor! I found Justin like that in the hallways!" Harry was nearly screaming. The words were just tumbling from him as he tried to explain. "I'm not the Heir of Slytherin and I'm not petrifying these people!"

The Headmaster nodded. "Harry, please, I believe you."

Harry blinked. "You do?"

"I do," Dumbledore repeated. "You are a second-year student who has never given me any sign of being a cold-blooded murderer or sociopath. Candace?"

It was Candace's turn to panic. "What? What did I do?"

"Please, Candace, tell me – you were the last person to see Justin unharmed, correct?"

"Yeah, I... I... "

"Do you recall anybody coming up behind you? Any strange sights or noises that could give us a vague clue to this Heir's identity?"

Candace was very flustered. "I... I... well, no, nothing that I can remember..."

"I understand," Dumbledore told her, trying to calm her down. "It is a bit traumatic to realize that you were just around the corner from a gigantic mystery monster."

"Actually," Phineas interrupted, "we're pretty sure that it's a snake-like monster. You know, considering that it's Salazar Slytherin we're talking about, who could talk to snakes, and took a snake as his emblem."

Dumbledore nodded. "A probably snake-like monster," he corrected himself. "But you don't recall anything strange, Candace?"

She shook her head, seemingly too flustered for words.

Dumbledore sighed. "Very well, then. The rest of the school body will most likely be shocked by my decision, but all of you are to remain here at school without punishment."

Harry felt as though he could leap into the air with relief. He was off the hook! Not that he was responsible for anything, he quickly thought, but he was glad that Dumbledore believed him.

"However, may I ask you something, Harry?" Dumbledore continued. "Do you have anything to tell me? Anything at all?"

Harry's stomach flipped over again, as he thought guiltily of the Polyjuice potion simmering away in the girls' bathroom, the creeping suspicion that he might be related to Slytherin, the strange voices that only he could hear...

"No, professor," he said, trying to look into Dumbledore's eyes without a trace of the lie he just told. "Nothing at all."

After Harry walked out of the Headmaster's office completely unscathed, the rumors around him seemed to triplicate. Some students went as far as to say that Harry was so powerful that he had bewitched Dumbledore, or at least threatened him with his probably snake-like monster. Harry could barely stand it. Around every corner, in every classroom, people stared at him as if they expected fangs to sprout from his mouth.

At last, Christmas came around. For most students it meant time off to go home and celebrate with their families, but to Harry it brought temporary relief. He was among the few that stayed at Hogwarts for the holiday season. This year especially, what with the whole "everybody getting Petrified" thing, students were eager to book their tickets on the Hogwarts express. Harry wasn't surprised to learn that Draco and his cronies were staying, too - even if he wasn't the Heir, Malfoy knew that no Slytheirn would come to harm.

Phineas had been somewhat cryptic about it, but he had dropped hints that he was planning another extravagant surprise for the school. (Last year he made a rest stop for Santa Claus.) When Harry went to bed on Christmas night, he was sure looking forward to the day ahead. Whatever Phineas and Ferb were making, it was going to be loads of fun.

The next morning, Harry awoke to the lovely scent of baked cookies wafting through the dorm. As he rolled over in his half-sleep, he dreamt that the house-elves had brought up cookies to celebrate.

"Harry! Harry! Wake up!" Ron suddenly shouted excitedly. "Get out of bed! You've got to see what Phineas and Ferb have done!"

Harry bolted upright. He rubbed his eyes. "What? What did they do?"

"Get up!" Ron repeated, running off towards the door.

Harry threw on his clothes and met Ron by the fat lady's portrait. The smell of delicious cookies was even stronger here.

"Just look at this," Ron said, pushing the painting open.

The cookie smell practically hit him in the face (not that that was a bad thing.) Harry could immediately see why – the entire hallway in front of his commons was now covered in tapestry-sized cookies of every shape and kind imaginable. Chocolate chip, sugar cookies, peanut butter...

"What do you think?" Ron asked Harry.

"I think," Harry said, scanning the hallways up and down, "that it's a very good thing that nobody here at Hogwarts has nut or gluten related allergies."

A little girl dressed in pink walked by with a platter of new chocolate cookies.

"Good morning, boys," she said, quite chipper, hanging the enormous cookies on a bare patch of wall. "Sleep well?"

"Yes," Harry blurted, a little bit surprised. "Are... are you one of Phineas's cartoon friends? Like the ones that snuck here before?"

"Well, since I'm a cartoon, you could safely assume that I am."

"Oh, yeah, I remember you!" Ron recollected. "You saved Harry from that fall during the Quidditch game."

Harry looked around at the delicious hall. "So this was Phineas's big plan? Covering the castle with cookies? I mean," he added quickly, "not like that isn't good enough, but I almost expected something a bit more... extraordinary, maybe?"

Isabella dusted her hands off. "That was the plan for the Gryffindor hallway. It's become the Hall of Cookies. Why don't you go take a look around the rest of the castle?"

Harry and Ron raced through the Hall of Cookies until it hit the huge, open space where all the moving staircases were.

Well, usually there were moving staircases there. Today they had been replaced with a colorful tangle of slides and floating trampolines.

"Blimey," Ron breathed, looking down at a group of Slytherins enjoying themselves on a trampoline. "I can't believe I'm saying this, but this is actually a lot better than just a castle filled with sweets."

Suddenly, Phineas and Ferb came sliding down from a few floors above on a bright red slide.

"Awesome!" Phineas exclaimed, landing on the ground with a rock star pose. "Now that we've fixed Blue 23-Y, we can say that the slides and trampolines have all been successfully installed."

Ferb gave him a thumbs-up and checked it off on the notepad he was holding.

"Oh, hey, guys!" Phineas said brightly. "So, how do you like the castle today?"

"It's brilliant!" Ron told them. "I don't want to seem ungrateful, but I have a feeling that... maybe... there's more?"

Phineas grinned. "I'm glad that you brought it up. Would you like to take a grand tour of our Fun Castle?"

"But... hang on a second, where's Hermione?" Ron realized, looking around. "I didn't see her in the commons this morning."

"Well, our tour is probably going to end near the girls' bathroom... does that answer your question, in an inexplicit and totally unsuspicious way?"

Ron was about to answer, but was interrupted by Professor McGonagall, who came storming in from an adjacent hallway.

"Flynn! Fletcher! I've been trying to find you all morning. Are you the ones responsible for the state of this school?" she asked them, rather sternly.

Phineas and Ferb stared at her.

"Well, no offense, Professor McGonagall," Phineas said after a while, "but do you know about anybody else capable of doing this?"

McGonagall glanced around her. "The first thing I'd like to say is this is probably, in my opinion, the most fun that Hogwarts has been in years," she admitted quietly.

"However," she continued, giving them a cautionary look, "most of the other teachers and staff members are not as enthralled as myself. Professor Snape is currently complaining to Dumbledore about this, and may be rallying others to his cause. He may even go to the Ministry about it."

Professor McGonagall leaned in closer. "I only wish to say this: Be careful, Phineas and Ferb. You may not know what you're getting into."

With that somewhat ominous statement, McGonagall continued down into the Hall of Cookies, her green robes billowing around her as she walked. Down the hallways, she stopped by Isabella, probably to give her the same warning.

"So," Phineas said, breaking the silence, "who wants to see the castle?"

The next thing Harry knew, he was whooshing down a purple slide, which twisted and turned and eventually dumped him out on a lower floor.

Phineas took them through the Hall of Mirrors, the Hall of Doors, the Hall of Gigantic Balloons, the Ball Pit Room, the Spinning Room, and the Pillow Fight room, just to name a few. They slid and they bounced from one floor to the next, until they eventually got to the girls' bathroom.

"This is it!" Phineas announced, sliding off his gazelle. "Dismount your ungulate and it'll go back to the Living Carousal room all by itself."

Harry jumped down from his crumple-horned snorkak and opened the door for the others. There to greet him was Hermione.

"Harry! Ron!" she exclaimed, running up to them excitedly. "I've got great news. The Polyjuice potion is all ready for us to drink," she told them proudly, pointing to the pewter cauldron sitting on one of the toilet rims.

Everybody crowded around the simmering cauldron. The potion looked more like bubbling, muddy water than anything else. It smelled like clay, and the overall effect was generally unappetizing.

"Should we do it tonight?" Ron asked.

"We have to," Hermione told him. "The potion doesn't keep very long. We have to use it within a few hours."

"But what if the real Crabbe and Goyle show up?" Harry wondered.

Hermione nodded towards a dark corner of the bathroom. "I've taken care of that already."

Ron turned around and, for the first time, noticed three large figures piled in a corner, (hopefully) sleeping. "What did you do to them?" he asked Hermione.

"Right, then, who'll have a glass?" Hermione asked, producing some mugs from her bag. "I was thinking that Harry, Ron, and I could drink the potion while Phineas and Ferb follow behind in the Invisibility cloak. After all, they are cartoon characters, and if they had Polyjuice potion for real-life Crabbe or Goyle the results could be disastrous."

Ron wrinkled his nose. "Does it taste bad?"

"Well, we are going to be putting little bits of Crabbe, Goyle, and Millicent Bulstrode into them, so if the potion doesn't taste bad as it is, rest assured that it will later. Do you all have your hairs?"

Harry and Ron went into their schoolbags and pulled out the hairs that they'd been secretly keeping since the Dueling club. Harry had collected Goyle's hair, Ron had snagged one from Crabbe, and Hermione had Bulstrode's. Hermione carefully ladled some of the Polyjuice potion into each of their cups, and they all dropped in their hairs.

"Eww," Ron said, squirming, as his potion turned a sickly yellow. "It looks like snot. How's yours, Harry? Want to trade?"

Harry's potion was a dull greyish-green. "No, thanks."

"We'd better go into a stall to... well, change," Hermione said thoughtfully. Harry and Ron nodded, and the three of them did so.

Moaning Myrtle floated out from one of the other toilets.

"Ooh, it's just going to be horrible, I know," she said with relish. "Who knows? It might never wear off."

Harry, shut in his bathroom stall, shivered at her words. But with half of the school petrified, that was a chance he'd just have to take.

"All right, once you drink the potion, you'll have about an hour as the Slytherins you look like," Hermione instructed. "Are you ready?"

"Yes," Ron said.

Harry took a deep breath. "Yeah, we're ready."

"Well, then," Hermione said tersely from a few stalls over. "Bottoms up."

Harry pinched his nose shut and tried not to think too hard about what was in the potion. He brought the cup up to his mouth and drank it in one gulp. As soon as the potion hit the back of his throat, Harry could feel himself changing. He was getting taller and fatter – his fingers were turning into pudgy sausages – his face was flattening – his nose was growing –

Then, it was over. Harry felt a bit woozy. He brought his enormous hand up to his face and examined it. His watch was painfully tight on Goyle's thick wrist, so he fumbled with it and finally managed to take it off.

"Ron?" Harry asked, and the word rang out in Goyle's low voice. "Ron, are you okay?"

"Is that you, Harry?" asked Ron (presumably). "Blimey, you sound just like Goyle!"

"Well, that's good, isn't it? Hermione? How are you coming along?"

There was no answer.

"Hermione? Is everything all right?" he tried again.

"I'm fine, Harry!" Hermione snapped. "Go check yourself in the mirror."

"Are you sure?"

"Yes, I'm sure! Now, go do it!"

Harry undid the clasp to the stall and stepped out. Goyle's feet were loud and heavy, and made a big thumping noise with every step. Ron's stall creaked open, and the spitting image of Vincent Crabbe stepped out.

Harry and Ron stepped up to the mirrors and examined themselves.

"Figure this will work?" Harry asked nervously.

"I certainly hope so. Oi! Phineas! Ferb! Do we look okay?"

Phineas nodded. "You guys look great!"

Ferb gave the two of them a thumbs-up.

Moaning Myrtle drifted down from the ceiling.

"You two look absolutely ugly," she told them. "Hideous. Like I said, I do hope it wears off. Then again, if it doesn't, you'd still be better off than her..." She cackled at them and dove into a toilet.

"Her?" Ron asked. "You mean Hermione? What happened?"

Harry walked to Hermione's stall and rapped on the door. "Hermione, are you coming or what?"

"Just... just go without me!"

"Are you sure you're okay?"

Over the top of the stall door, Harry could see a pair of furry ears.

"Hermione..." he began.

"It wasn't Millicent!" Hermione sobbed. "It was her cat! I look like a cat, okay? Just go without me!"

"I'm sorry!" Harry said quickly, backing up from the door. Hermione looked like a cat? How were they going to explain that to Madam Pomfrey? But Harry supposed they had other things to worry about.

"Come on, guys," he said gruffly, handing Phineas and Ferb his invisibility cloak. "Let's go and find the Slytherin commons."

It wasn't as easy as Harry thought. Nobody had ever told Harry where the Slytherin commons were, and he'd never seen them in the school. He figured that he could just ask other Slytherin students, but most of the other students seemed to avoid Crabbe and Goyle, apparently.

"A half hour's gone," Ron grunted. "And we still haven't found the commons."

"I'm trying," Harry snapped at him, turning around another corner hopefully.

"Why don't you just use the Marauder's Map?" Phineas suggested.

"That's the next book, Phineas," Harry said absentmindedly, running down a new corridor. Phineas and Ferb had decorated this one with a musical theme in mind. The floor was a huge piano, and assorted instruments lined the walls. A group of students was jumping around on the piano, trying to play songs.

"Hey!" Ron shouted desperately, trying to run with Crabbe's gorilla arms swinging wildly around him while he did so. "Hey! We're... we're, um, a bit lost. Can you tell us the way to our commons?"

"Our commons?" one of the students, a girl, scoffed. "I'm in Ravenclaw."

"Crabbe! Goyle!"

Harry and Ron spun around. Draco Malfoy was walking down the hallway.

"Been looking for you two all night!" he said nastily. "What, were you having fun with the Muggle's stupid decorations?

"Come with me," he ordered, turning around and pointing. "I've got something absolutely hilarious to show you."

Harry and Ron exchanged glances. Something hilarious? Had he just Petrified another student?

Harry, Ron, and the invisible Phineas and Ferb followed closely behind Malfoy. Malfoy reached the slides and trampolines and scoffed.

"See what that Muggle's done?" he asked, punching an orange slide as he walked past it. "He's ruining our school. Honestly, slides? Trampolines? I've already informed my father, and the Ministry will certainly be hearing about this."

Draco took them down whatever obscure, intact, still-staircase staircases he could find, and tried to turn a blind eye to all of the fun hallways they passed. Harry saw that they were going deeper and deeper into the castle. He wondered if they were below the moat, or still above ground. Eventually, Draco turned down a lonely corridor, which Harry and Ron had actually passed a couple dozen times as they tried to find the entrance.

"What's the password again?" he asked Harry.

Harry broke out in sweat. "Oh... uh..."

"Oh, right – Pure-Blood!" he announced.

The bricks of the wall slid apart, admitting Draco, Ron, Harry, and the invisible Phineas and Ferb. Harry stepped inside. It was a lot darker than the hallways, so his eyes took some time to adjust. The very first thing that Harry noticed was the large, strangely green-tinted windows. Then he realized that the light filtering through the windows was so green because the windows were underwater. As he thought it, the giant squid drifted lazily by, along with other fish and strange, shadowy shapes. It was, Harry admitted to himself, pretty cool, kind of like hanging out in an underwater shipwreck. The entire commons was bathed in the greenish light, and light refractions danced around.

Draco pointed at a green sofa. "Wait here. Dad sent me the newspaper clip. I'll fetch it from my suitcase."

He raced down a staircase, leaving Harry and Ron to wait by themselves. That wasn't an exaggeration – Harry and Ron (and Phineas and Ferb, of course) were literally the only other people in the commons. It was eerily quiet.

"Where is everybody?" Ron asked, looking around.

Harry shrugged. "I honestly think that they're out enjoying the Fun Castle."

"But Phineas is a Muggle. Shouldn't they all be sulking in here and refusing to have fun with it?"

Phineas's disembodied voice sounded from a spot somewhere to their right.

"Actually, Ron, not all Slytherins are evil, extremist snobs like Malfoy and his cronies. We talk to a lot of Slytherins in the hallways. They haven't seen a lot of regular old technology, and they think it's kind of cool."

Just then, Draco returned, clutching a bit of newspaper. "Here," he said, thrusting it at Ron with a wide smile. "Read this."

Ron looked at the paper for a while, forced out a laugh, and handed it to Harry. He read:

Inquiry at the Ministry of Magic

Arthur Weasley, Head of the Misuse of Muggle Artifacts Office, was today fined fifty Galleons for bewitching a Muggle car. Lucius Malfoy, a governor of Hogwarts School of Witchcraft and Wizardry, where the enchanted car crashed earlier this year, called for Mr. Weasley's resignation.

"Weasley has brought the Ministry into disrepute," Mr. Malfoy told our reporter. "He is clearly unfit to draw up our laws and his ridiculous Muggle Protection Act should be scrapped immediately."

The crash of the enchanted car is not believed to have been an intentional act by Mr. Weasley, although the car did manage to completely destroy the Herbology room of Hogwarts and an entire crop of mandrakes. Though the Herbology teacher expressed her frustration at having to wait a whole year to bring a new batch to maturity, she tells us that the new mandrakes she planted are coming along nicely.

"Well?" Malfoy demanded. "Isn't it funny?"

"Ha ha ha," Harry said dryly, handing the newspaper back to him.

Draco leaned back on the sofa leisurely. "I've got to say that this year has been the best ever for me. First, the Weasleys get slammed for a flying car, and now the Chamber of Secrets is opened. I don't understand how people can say that Potter is the one behind it. What makes them think that he's capable of something like that?"

Harry and Ron leaned forward, waiting for the confession...

"I wish I knew who it was," Draco said wistfully. "I'd love to help them."

Harry's mouth dropped open in shock

"What?" he asked. "You... you don't know? Haven't you got a clue, at least, or something?"

"How many times do I have to tell you, Goyle?" Draco said exasperatedly, dusting something off of his robes. "I haven't got any idea who it is. My dad was here fifty years ago, and the same thing happened back then. He wouldn't tell me a lot, but there was a student who got expelled – but not before a student died."

Harry paled. Somebody had actually died from this monster? And how long before it happened again?

"You want to know who I hope it is?" Draco asked. Without waiting for a reply, he said, "I'm actually having a rough time deciding. My mind was set on Grainger before, but now with all the stuff that Phineas has been doing, I'd nominate him. Slytherin would surely want the real Muggle weeded out before the Mudbloods."

Ron, forgetting himself, stood up in outrage.

"What the matter with you?" Draco asked.

Harry looked up at Ron. He could see bright red hair appearing in Crabbe's dull, black hair. The potion was wearing off.

"We have to go," Harry said, standing up as well.

"What for?"

"I've got a stomachache," Ron grunted, clutching the red part of his hair and beginning to leave.

Harry felt himself beginning to shrink and thin out. "I'll see him to the hospital wing," Harry said, as he and Ron broke into a run and hurried out of the commons. They didn't stop running until they reached the girls' bathroom again.

"That was too close," Ron said, gasping for air. He was completely Ron again, with no trace of the gorilla-like Crabbe left.

"Phineas, Ferb? Are you there?" Harry asked the air around him.

There was a swish of fabric, and Phineas, sitting on Ferb's shoulders, appeared.

"Yes, yes we are," he said, hopping down from his stepbrother. "That was quite the escapade."

"Yeah, and for what?" Ron demanded, slouching down against a wall. "Malfoy isn't the Heir of Slytherin. We wasted months of time and effort."

Harry didn't know what to say. Truth be told, he completely agreed with Ron The entire endeavor had been a waste, and now they had no idea who could be the Heir. Nobody else was nearly as pure-blood extremist as Malfoy.

"We should check on Hermione," Harry said, trying to take his mind off of their failure.

Harry, Ron, Phineas, and Ferb walked back to the bathroom stall. It was still closed, and the tips of furry ears were still showing above the door.

"Hermione, we're back," Ron said, knocking on the door. "Malfoy isn't the Heir. He hasn't got a clue who is."

They heard an audible sigh.

"Rats," Hermione said. "There goes our solitary lead, I suppose. Hmm. Rats," she muttered. "Rats sound really good right about now..."

"We need to get you to the hospital ward," Harry told her.

"No!" she screamed. "I don't want anybody to see me like this."

"It truly is awful," Moaning Myrtle told them in a giggle, floating in from around a corner. "You should see her tail."

"Hermione, you've got a tail?" Harry asked.

"Please, just go away!"

Phineas stepped up. "Could I offer a suggestion?"

"What?" Ron asked.

"Well, Ferb and I could try the Homorphus charm. It might do the trick!" he told them brightly. "And if it doesn't, Ferb has already studied advanced Transfiguration, and could probably make her look just like she did before.

"Of course, Ferb and I also happen to know cosmetic surgery should neither of those work."

Ferb, already dressed up in a surgeon's uniform, rushed a white operating table into the bathroom from goodness-knows-where.

"Try the Homorphus first," Hermione said immediately. "Please, I'd rather we try that one."

Phineas and Ferb pulled out their wands. "Sure thing!"

Phineas's hand-made wand never ceased to amaze Harry. It was masterpiece of technology, constructed out of a video game, some wood, and a chocolate frog. Yet it worked, well enough that the teachers didn't realize he was a Muggle until the wand was blown to tiny mechanical pieces by Quirrel last year. Now, he and his stepbrother were casting some kind of strange, advanced charm – one with real magic, and one without any. Harry saw the furry ears shrink and disappear behind the stall door, and might have caught a glimpse of a brown tail before it vanished completely.

"It worked!" Hermione said joyously. She opened the stall door, and Harry was relieved to not see any cat-like features on her.

"Thanks," Hermione told Phineas and Ferb. "I certainly didn't want to go to the hospital wing like that. Besides, Madam Pomfrey would have surely told Dumbledore, and we'd have been in trouble."

Ron interrupted. "Let not forget, guys, that we've just wasted a month for nothing. Malfoy isn't the Heir of Slytherin."

The five of them stood there, feeling a bit defeated. Ron was right, Harry supposed. They would have to start all over.