Disclaimer: I own very little.

A/N: This is a response to the third wave of the Master & Wolf FQF. The challenge is: 84) One of the worst things about having Sirius gone is that there's no one to stay with Lupin when he transforms. But then, an animal starts to join him during the full moon. They quickly bond. Lupin is convinced it is an Animagus, and is determined to hind his real identity.

An insane fluff plot bunny (yes, I have those, too) that somehow managed to leave my mind and pour out to my comp... No sense ahead. As of how this got started, I was playing with the idea whether a werewolf's wolf form could be another gender than their human form, and, well, this is what came from that idea combined with the challenge.
My thousand thanks to Lyssepoo for betaing this.
...The title sucks. But I wanted a title that would begin with the letter "Y", so, my bad.
WARNINGS: MPREG. Well, not really, but kind of... Oh, and of course SLASH RL/SS.

You Never Know
The nearer the moment of full moon came, the more anxious Remus became.

He knew what the wolf would be like, as he'd once before had to settle to a life with nobody as his companion through the full moons. That was also the reason why he hadn't wanted to stay in Grimmauld Place with people around - he knew all too well that the wolf would go on a rampage, and he didn't want to risk the others if it came too much for him to control even with the help of the Wolfsbane Potion.

Once the exact night of transformation came, he was in his little cottage in the middle of nowhere. He didn't think he could transform in Grimmauld Place - of course everyone would stay away, so as not to unnerve the wolf, but the house was full of the scent of both Sirius and Padfoot. It was almost unbearable to him as a human - to the wolf, it'd be a nightmare.

So, as the night came nearer, he undressed himself in the middle of his tiny living room. Folding the clothes into a neat pile which he placed on the nearby shelf, he sat down on the floor, waiting for the moon to come up.

Suddenly, a wave of pain hit him. Remus bit his teeth together as his muscles were stretched, his bones bent, and mouth stretched out into a muzzle. Fur grew from his skin, his ears moved to the top of his head, and a tail spurted out from him.

Just as suddenly as the transformation had begun, it was over. Then, he rose to his four legs - or, rather, she rose to her four legs.

That was a truth he'd never told anybody but his friends - his friends consisting of the former Marauders, Nymphadora Tonks, and Kingsley Shacklebolt - and wouldn't tell anybody else, if he just could avoid that. A werewolf's wolf form's gender was confirmed in two ways. If they were born from lycanthropic parents and thus inherited the curse, the wolf was the same gender as the human. If, however, they got later inflicted with it, the wolf was the same gender as the wolf that had bit the human in the first point.

And, as Remus had been bit by a she-werewolf, his wolf form was female.

So, Moony rose to her legs, shaking herself slightly. Sniffing at the scents of her home, she padded towards the door. Even though she was now alone, she just had to run around for a while. It would make the ache of her muscles more bearable - and, hopefully, the painful memories.

As she slipped outside, however, she caught an unfamiliar scent. Slowly turning around, she saw a wolf. A he-wolf.

He was almost twice as big as she was, which was really big, considering that she was bigger than most females due to her lycanthropy. His fur was night-black, his muscles well-shaped, and there was an understanding glint in his eyes. Looking wary, he took a tentative step towards her.

Moony went nearer, sniffing at the stranger's scent. She sensed no threat from this wolf, so she was not afraid. Besides, she also noticed that this was a normal wolf, not a werewolf like she. Normal wolves never messed with werewolves, no matter what was their size, or even if they had their whole pack with them. And this wolf was alone. So, no reasons to be afraid.

As they'd hastily got to know each other's scent, Moony sat to the ground. 'What are you called?' she asked from her companion.

'Shadow,' the stranger replied - or, rather, gave her the idea of a shadow, as wolves did not use real words. But, the idea was enough - cool air, darkness, a swish of motion, along with an odd lightness accompanied by mysterious weight. Shadow. 'Who are you?' he then asked in turn.

'Moony,' she replied. The scent of night, sounds of distant howling, pale light on tree leaves and grass wet with night dew, and a slide of silver that made her unvoluntarily shiver - all that formed her name. The name had been given by her friends, who were now all gone, or worse - to wolves, nothing was worse than bertraying the pack.

He nodded. 'A good name,' he said, still watching her intently with his jet-black eyes. 'You're one of the cursed,' Shadow noticed, taking a step backwards in wary respect.

Moony nodded in response. They both knew that Shadow had known her kind before even the first sight, before they had tested the other's scent for the first time. But, it wouldn't have been polite to mention it before the usual formalities. And wolves were all for politeness.

'That explains it, then,' Shadow continued after a moment of silence that was very usual to any conversations between wolves.

'Explains what?' Moony asked after the respective pause.

'Why you smelled of a male before the dawn, and of a female after the moon came up,' came the reply. Once again, Moony's human part was fascinated by all the feelings Shadow sent to her instead of words - 'male' was a mix of aggressiveness, harshness, sharpness, and strength, while 'female' was made up of softness, wariness, speed, and fluid motion - not to forget a slight mention of cubs.

'Yes,' she replied, 'that's the reason.' Then, as the other wolf didn't seem to be going to say anything, she asked, 'Will you run with me tonight?'

After a moment, Shadow nodded. 'That will be a honour to me,' he said, and Moony didn't doubt his words at all.

Side by side, the two wolves departed to the nearby forest.

As the dawn came nearer, two exhausted wolves walked out of the forest, towards the little cottage. They'd spent all night running and hunting through the forest. Moony's human side had kept in control, however - somehow, Shadow's presence seemed to make it even easier, just like her Animagi friends had done before.

This wasn't even the only reason why she suspected Shadow to be an Animagus, she thought, as she bid goodbyes to her new friend and slipped inside through the doorway. Not only could she communicate with Shadow about everything without any problems at all - even the most intelligent animals, like dogs, failed to understand certain aspects of human life, and thus demanded many explanations - but also the he-wolf seemed to be very knowledgeable about most things concerning only the humankind, as well as extremely intelligent.

Besides, there were no wild wolves in Britain.

With these thoughts in her mind, Moony fell asleep. still loves

The next morning - or, rather, the next day - Remus awoke to see a man with beetle-black eyes watching him.

"Severus?" Remus croaked with a raspy voice.

"Dumbledore sent me to check on you," the Slytherin explained. "Drink this." He handed Remus a goblet, which the werewolf accepted.

Remus sipped the potion, absently noticing that he was in bed and covered up with a warm blanket. For a moment he thought about thanking Severus, but the warning glint in the beetle-black eyes told him not to.

"Severus?" he asked as he handed back the empty goblet.

"Yes, Lupin?" came the snappish reply.

"Could you please go and look at the most recent Ministry registries, and check if there are any wolf Animagi in Britain?" Remus asked as kindly as he could.

"Why, lacking company?" Severus sneered. "And why don't you go yourself, or better even, owl and ask for the list of registered Animagi? Even my students do that all the time, you know."

"I can't," Remus replied softly. "Due to my werewolf status, I'm not allowed to receive any official documents that don't have any mentions of me - and not even most of those that do. And to enter the Ministry building, I would have to show my ID tattoo and submit to a personal search. It's rather humiliating, and most probably they'd anyway make up some prohibition to prevent me seeing the registries."

For a moment, Severus kept quiet, just watching him with the unnerving jet-black eyes. Then, very slowly, he nodded. "Okay, I'll do it." Then he turned around and swept out of the room, then out of the whole house, and Disapparated.

After the next Order meeting, Severus came to Remus. "I looked at the registries," he said without any further formalities. "There are no wolf Animagi in the whole country."

Remus nodded slowly. An unregistered Animagus, then. "Thank you, Severus," he said. "I owe you."

"So you definitely do," the Slytherin murmured, then again swept away.

The odd wolf came back the next full moon. And the next, and the next. Every time, they'd run in the forest, or just lay together on the floor of Remus's little cottage - always depending on Moony's current condition, as some transformations were more difficult than others.

Moony soon learned to trust her unusual companion, and between full moons, Remus almost longed for the next full moon, because that meant that Shadow would come again. The other wolf seemed to be the only creature who could understand him after Sirius's death. The truth that they were both in wolf form somehow made it easier - their feelings were stronger and rawer, with no barriers of humanity keeping them down.

One day, Remus did what he wouldn't have thought he'd ever do - told about the gender of the wolf to somebody. To be exact, Harry and his friends. Somehow, the truth that some stranger knew about this change, and approved it, made it a lot easier to him to admit it to some of his less near friends.

Occasionally, Remus wondered who his mysterious companion really was. As there were no wolf Animagi in the registries, he figured that Shadow must be an unregistered one - which meant that he was a powerful and intelligent wizard, as he'd managed to complete the transformation without any help. That was a truth Remus had to respect, since he knew very well the difficulty of becoming an Animagus, having seen his friends' efforts for it.

They become closer and closer. Even the truth that Moony was in essence male didn't disturb her companion playfully teasing her. One night, being on an extremely playful mood, Moony decided to give in to her temptations.

That night, their howls were heard far away.

Next chapter:

Severus makes a shocking discovery.