Polyjuice Potion

His meeting with Dumbledore had shaken Harry so badly that he twisted and turned for hours in his bed before he finally fell asleep. Luckily, his subconsciousness was as exhausted as he and missed the opportunity to harass him with weird dreams.

Harry awoke early and as nervous as he was impatient for finishing his Polyjuice Potion. He went to check on it before breakfast. The recent changes were disheartening. On Friday, it had still been a wonderful violet potion. Its aroma had been rich and it had been a pleasure to stir the fluid. The last violet streaks were slowly vanishing. Soon it would be a slushy grayish-brown mass.

Unable to do anything about the potion Harry checked the stone circle right after breakfast. It was chilly and Harry could suddenly understand why Nagini had announced to retreat. As a snake, she had no control over her body temperature after all.

She was not to be found which wasn't a real surprise. He had never met her before noon.

Harry went back to the castle and finished his homework faster than he was keen on. Grumpy at the Professors, he spent the next hour trying to unearth information on Maledictuses. He found not even out how to write the word. So either there was no information on the curse in the school library or they were sealed away in the Forbidden Section. Or maybe he had no idea where to look for them?

After lunch, Harry became too restless to spend another minute in the library. He decided to fetch Nagini before he finished the potion and thus abandoned his plan of surprising her with a drinkable vial full of Polyjuice.

Back at the stone circle, he couldn't spot Nagini until he nearly stepped on her tail – why wouldn't she wait for him at the same spot two days in a row?

In a manner of greeting Nagini hissed, "Why do I never smell a female on you?"

Harry smirked because his friend must have had a bad day too. "Is that your way of asking whether I have a girlfriend?" He stepped closer but did not sit down. "Or was this an attempt to relieve the tension?"

It was not unusual for Nagini to not answer certain questions. Harry had always thought she ignored them. This time however he imagined her to roll her eyes at him. Over the course of the day, he had so far done everything to avoid imagining her as a witch but his resolve crumbled now that he was here with her.

The most natural for him was to imagine her as being of equal in age as him. However, he knew that was wrong. He guessed that she was close to Professor McGonagall in age but despite that fact she would take the appearance of a preteen witch once she drank Polyjuice of herself. She had turned into a snake before she got her wand after all.

Nagini interrupted his musings, "Have you talked to Dumbledore or McGonagall?"

Harry nodded in confirmation. "I met with Dumbledore."

The witch twisted her snake body, nervously rubbing her scales against each other, "He told you what a Maledictus is?"

"Yes." Harry nodded. He had no idea what to say. Should he tell her that he was sorry for her? He felt like that was not what she wanted to hear.

Once more Harry got drawn away from his thoughts by Nagini, "Is that why you're not sitting down? Is our friendship over?"

"No! We are still friends." He hastened to explain, "I'm not sitting down because I want to move you into the castle. I told Dumbledore that I wanted to and he did not object." Which qualified not explicitly as permission to bring Nagini into the castle but as his excursions into the Forbidden Forest proved, Harry hardly cared about inconvenient restrictions.

"I'm sorry for keeping that a secret from you."

"I understand your reasoning." Harry smiled at Nagini. "You can't change into a witch anymore. Therefore, it was of no importance to tell me." He made the first steps in direction of Hogwarts but stopped when he noticed that Nagini was not following him.

"What if I don't want to accompany you into the castle?" She asked cautiously.

The question surprised Harry. "Um, well,... that would be your decision to take." He scratched his head helplessly while wondering whether he should outright tell her about the Polyjuice Potion. But somehow this felt more like a general discussion. "I think spending the winter in the warm castle would be preferable to hiding in the Forbidden Forest."

"I'm doing alright," Nagini said defensively.

"Sure you do." Harry nodded energetically. By now, he felt quite secure that this was indeed a general discussion – maybe about pride or independence? "I don't mean to say that you can't take care of yourself at all. I'm just offering you an alternative. Maybe I'm even selfish about this matter because I would really like to keep talking regularly to you."

Nagini moved a short distance in his and the castle's direction. She stated categorically, "I'm not your pet."

"No! I would never think that." Harry hurriedly exclaimed, "That would be weird. Hedwig is a pet." It was almost funny that he had always thought like this about her. He tried to express his reasoning, "Even before yesterday, I've never thought of you as an animal but always a magical creature on par with the centaurs." In a smug tone, he added, "And I've been right. You've been a witch all along."

Nagini regarded him with a penetrating stare. "Few wizards talk about centaurs like they are more than beasts."

"Well, some wizards think they are better than anyone." Harry shrugged his shoulders, "Ironically, I think they are the scum of the earth."

Nagini hissed in a way that Harry had always thought was her equal of an amused laugh.

When she slithered after him, Harry breathed a sigh of relief. Sneaking through the castle, they only had one critical moment. However, the Marauder's Map allowed them to sidestep the almost panicking Ravenclaw who was sprinting in direction of the library. Apart from that, they came not even close to running into any student or teacher. Everyone was busy with whatever they did Sunday afternoon.

Nagini complained about climbing the stairs up to the seventh floor were the Room or Requirement was hidden but that couldn't be helped. Soon enough, Harry walked up and down in front of the wall which transformed into the hidden door. He explained, "You have to pass this wall three times while thinking about the place you need."

The entrance appeared. "If you do it right, you'll get access to the Room of Requirement."

Harry held the door open for Nagini. She hissed approvingly, "The floor is warm."

Once her whole body had slithered past him, Harry followed her. The first thing he did was bend down and touch the stones. Had the room magically created a floor heating or was it a warming charm? "I guess the Room of Requirement changed to suit your needs."

When Harry looked around he barely recognized his potions lab. The huge cauldron was still there and his table as well. Apart from that everything had changed. There was a couch, a bed, a huge wardrobe with weird dresses, and even an open door beyond which he could see the tiles of a bathroom. It was like a small apartment!

Nagini interrupted his inspection, "That's the potion?" She was close to his cauldron and her tongue darted in and out of her mouth to take in the smell.

"Yes, that's the Polyjuice Potion I've been brewing." Harry took a look at its color and found that it was not yet time to add the lacewings. "It'll be done soon."

Nagini's head rose up to take a short look at the simmering liquid.

"Do you know what Polyjuice Potion does?" Harry asked gently. He could not remember whether he had ever told her what kind of prank he had been preparing since before they even met. They had talked about so many things, he had completely lost track of them.

Her answering hiss transmitted Nagini's lack of interest better than any word.

Harry realized that he had never told her about his prank. She had discouraged him about it at every opportunity. Everything else about him or the castle interested her but not his prank.

Harry watched Nagini closely and started explaining, "Polyjuice Potion allows wizards and witches to change appearance. If you put someone's hair into the potion and drink it, you will turn temporarily into that person." She was clearly intrigued!

Harry picked the hairbrush from the table. "Dumbledore gave me this." When Nagini showed no signs of recognition he told her, "This is your brush and those are your hairs." He pointed at them. "Dumbledore thinks, if you drink the potion with your own hairs, you'll get your human body back. At least temporarily."

Nagini had become completely stiff. She did not even blink although that was due to an inability of her reptilian eyes. "And you'll give me some of that potion?"

"Some?" Harry almost choked on the word. "This is all for you! You're my friend! And this can clearly help you. I'm not going to waste a single drop of this on a stupid prank!"

It took her an eternity to say something, "I've got nothing to give you in return,"

"You don't need to give me anything," Harry said categorically. "You've not asked for anything in return for showing me the fluxweed when I had not enough. Or for leading me out of the forest when we met. We're friends. And friends should help each other if they can."

Despite the couch, Harry sat down on the floor. After a moment of hesitation, Nagini placed her head in his lap and snuggled into his back - for once not in search of his warmth. She hissed, "You're the best friend I ever had."

"I feel the same way,"

They spent minutes in comfortable silence. "Aren't you curious what clothes the Room of Requirement has chosen for you? Let's take a look at them!"

A lot of the cloaks and robes were damaged. Some had stains. The rest represented all the levels of hideous Harry could think of.

The time to add the lacewings rolled around sooner then either of them had expected. Harry flipped an hourglass of the right size to cook an egg and stirred the potion clockwise. When the last grain of sand left the upper half of the hourglass, he added the lacewings. He turned the small hourglass around and stirred counterclockwise.

"That was that," Harry fetched a normal-sized vial and filled it with a dose of the Polyjuice Potion. He pulled a single hair of the brush and measured how much length he'd have to add. Wasting the most precious ingredient was the last he wanted to do.

Upon adding the hair, the potion turned green with black streaks. The appearance reminded Harry of Nagini's scales. "Okay, this is it."

Nagini slithered closer and opened her jaws. Since Parseltongue consisted entirely of hissing noises she had never had a reason to open her mouth. Thus, Harry registered in surprise how far she could open her jaws. But his eyes became truly wide when he saw how many teeth Nagini actually had. Harry had expected to find only two very long, retractable poison fangs. But instead of those, she had two rows of fangs on each side of her jaw.

The potion poured down Nagini's throat without any visible swallowing. For a very long moment, nothing happened. Wizard and snake looked questioningly at each other.

"Do you feel something?"

Instead of answering Nagini curled up. Her skin started moving. In shock, Harry watched Nagini's skin move like her flesh was boiling underneath of it. He was close to panicking when her head started deforming in a way that made clear that the Polyjuice Potion was working correctly. Nagini shrunk considerably. Her scaly skin turned pale and black hairs sprouted out of her human head.

Right in front of Harry's eyes, Nagini turned into a witch. An adult one. Not a little girl. Or an elderly lady. Nagini definitely turned into a very healthy and very female woman.

Harry hurried to the wardrobe and picked the first cloak he came across. He rushed back to Nagini who was staring at her own hands in wonder and placed the cloak around her slender shoulders.

"It worked?" Her female and no longer hissing voice cried in surprise. "My voice!" Nagini pulled the cloak Harry had just put over her off again and inspected herself. "It really worked!"

Harry turned away. He decided to stare at the cauldron with the rest of the Polyjuice Potion. He would not glimpse or even think about the naked witch in his back. He had already seen too much. But the temptation was there. The little he had seen made him want to look at her really badly.

He was very glad when he came up with an idea to make her leave the room, "There should be a mirror in the bathroom."

Instantly, the sound of naked feet running on a stone-floor could be heard. A squeal made clear that she had found a mirror, "Look at me! I've not aged a single day!"

Harry was very aware of the fact that Nagini had no age problem. He tried to rearrange his trousers so his erection wasn't too obvious. He knew he shouldn't blame himself because she was good looking and she was the first woman outside of a magazine he had ever seen naked. Nonetheless, he still felt bad about his hard-on. She was first and foremost his friend. She trusted him. And she had been living through years of hardships and did not deserve someone who lechered after her!

Soon, the rushing of running water, the brushing of teeth and a lot of other bathroom sounds could be heard.

Harry busied himself with magically bottling the Polyjuice Potion. While doing so, a smile crept on his face. He was glad and oddly proud about helping Nagini.

At some point, his mind registered that there were no more sounds coming through the open bathroom door. When he glanced in slight worry over his shoulder he saw the naked witch pout at him, "I was hoping you'd visit me in the shower..." She let the cloak slip from her shoulders, revealing that she was still completely naked. "But I guess it doesn't really matter. We can just make up on the lost time."

Harry's protests like "I don't want to take advantage of you!" were laughed away. He ended up on the bed just as naked as Nagini getting guided through his first and second time by the very eager witch.

A/N: In regards to the rating of this story, I'm copying a technique of Gandalf's Beard. You'll find a more explicit version of this chapter on AO3.