This one's for MoonStar, and Sirius's Crazy Chick: thanks for the feedback, you're right, it does help - I'm totally new to FanFiction.com and personally I'm amazed I managed to figure out how to make this thing go into chapters. Computers are not my forte. But everyone else, please review! Thank you all ~M~

Lupin rolled up his sleeves, and looked at the others grimly. "You'd better go and find Ron," he suggested, "While I deal with this. I don't know where he'll be… but at least, I think, we can rest assured he isn't dead. But he might be hurt – Severus, could you brew something up for him? I haven't a clue what the symptoms of fighting with a Brollachan would be like… you'd know better than me…"

Snape muttered something under his breath that Harry thought sounded distinctly like 'flattery won't get you anywhere' but nodded curtly and left the room before anyone could say anything else to him. Harry looked at Hermione, and then at Sirius.

"I'm going to look for Ron," said Harry. He didn't know if Sirius would try and stop him, but he didn't care if he did: and, from the look of things, Hermione didn't either. As it was, she'd reached the door before either Harry or Sirius had moved.

Sirius suddenly sprung to life. "Yes," he said, following Hermione. Then he paused. "Moony – you'll be careful? Are you OK doing this by yourself?"

Harry didn't hear Lupin's response as he joined Hermione outside. All that was important now was finding Ron.

He, Hermione and Sirius traced their way back down to the small stream where Ron had accepted the Selkie's challenge, and looked around for any signs of him. But they found nothing; Harry didn't know whether to be disappointed by this, or relieved that they hadn't found a corpse.

"What's this?" asked Hermione suddenly, stooping to the ground and picking something up. They were now a good one or two miles away from the stream: they'd been searching for at least three hours, and panic was deepening. Harry looked at the object in Hermione's hand, and gasped.

"It's the Hubble gum wrapper!" he exclaimed. "Ron – he must have dropped it here!" And he looked around everywhere – left, right, up, and down for anything else that might indicate Ron's whereabouts.

"The wind might have just blown it here," said Sirius doubtfully. But Harry shook his head.

"There is no wind," he said. "Ron must be here, somewhere…" He thumped his hand against a tree in annoyance.

A second later, Harry was lying flat on his back in a pit that hadn't been there a moment ago. Startled, he peered up at Sirius and Hermione's astonished faces: He didn't know quite how he'd done it, but he appeared to have activated some form of trap. He was getting remarkably good at that, he thought ruefully.

Sitting up stiffly, he began to call up to Sirius to help him out. But the words died in his throat.

Lying next to him, his face smudged with dirt and his eyes closed, was Ron.

Sirius and Hermione managed, with much difficulty and quite a lot of accidental acrobatics, to pull both Ron and Harry to the surface again. Ron hadn't spoken since Harry had found him: in fact, he'd barely even moved, and Harry was terrified that he might be dead. But Sirius assured him that he was breathing, and he shouldered Ron's weight as though he were nothing more than a sack of potatoes and set off back to the hut in silence, Harry and Hermione scampering alongside Sirius quickly in an effort to keep up.

It took them less than an hour to reach the wooden shack, and when they did so they halted at the small door. Snape was stood outside it, listening through the keyhole to the sounds from within – a series of crashes and small explosions – and he twisted round so violently when Harry and the others approached that he lost his balance and fell into the door. It swung open just as something appeared to blow up inside: great billows of smoke flew out towards them and Harry, Hermione and Sirius flew inside to see what was happening – treading on various bits of Snape that were draped over the threshold as they did so – and came face to face with Professor Lupin, sitting quietly in a chair.

Sirius put Ron down on the table.

"Well?" he demanded. "What happened?"

Lupin sighed. "It's gone," he said. "Though I'm not sure if I killed it… It disappeared just as you came in."

Snape had picked himself up and stood there, brushing himself down ineffectively with his hands and glaring at everyone.

"I'm afraid I put an end to our not using strong magic, though," went on Lupin. "If Voldemort can sense it then he'll be on to us in no time. How's Ron?"

Everyone's attention was switched to Ron as though somebody had flicked on a light. He had not changed since the last time they'd checked.

"I'm not sure," said Sirius, frowning. "He's been like that since we found him – I'm not sure if he's just unconscious, or if he's been hexed."

Lupin also frowned. "We'll have to see what we can do – and do it as quickly as possible," he said. "Let's get Ron to bed, and then work out what needs to be done."

"Ha!" exclaimed Snape. "And how do we know that you are Lupin? How do we know that you aren't the Brollachan – that you haven't killed him – and taken on his form?"

Harry paused, as did everyone else. Snape had a point. Lupin – or what looked like Lupin – smiled wryly.

"Well, there you have me, Severus. I honestly don't know. You'll have to just believe me – or not, I suppose… Would you imagine that a Brollachan takes on the form of its victims to the extent of becoming a werewolf?"

He had seemed to be musing, but Snape's eyes lit up. "I wouldn't have thought so," he said softly. "But you know… there are ways to find out whether or not you're a werewolf…"

Sirius stepped forwards, placing himself in between Snape and his friend.

"No," he said firmly. "Remus has put up with enough from you… The way you've treated him… I thought you'd have grown out of your petty little games by now, Snape. First you beat him nearly unconscious as a wolf; you haven't had the decency to speak to him civilly the whole time we've been travelling – even though he's stopped me from punching your greasy face a good few times – and now this. Of course it's Remus. Isn't it, Moony?"

"Well yes, as it happens," replied Lupin. "But I don't expect anyone to bel– "

"Don't you dare threaten me," Snape interrupted, snarling at Sirius. "I'm acting on all our behalves here – does it even matter to you that by accepting his word that he isn't the Brollachan you're placing all our lives at risk? Or wouldn't you care? Just be exchanging one monster for another, I suppose."

Lupin winced. Sirius looked livid.

"How dare you!" he shouted at Snape. Harry tapped his fingers nervously against the table and looked at Ron: he hadn't moved since they'd brought him in, and Harry was desperately worried about him. How could he alert anyone's attention to him, though? Snape and Sirius looked just about ready to kill each other again: the tension which had, somehow, remarkably been contained the last two days was beginning to erupt again and Harry personally didn't think they could have chosen a worse time for it.

Sirius was still shouting at Snape. "How dare you – you – call him a monster?" he demanded. "Ever heard the expression 'the pot calling the kettle black'?"

Snape growled a feral growl, and lunged towards Sirius, who seemed to welcome him gladly.

"It was like this at school," sighed Lupin to the others as they rolled about on the floor, each taking every possible opportunity that presented itself to get in a good kick or punch, in what Harry decided was quite possibly the dirtiest fight he had ever witnessed. "I suggest that we leave them to their own devices for a while and see to Ron. I'm sure they'll wear each other out eventually – although maybe you don't believe it's me?" He took Harry and Hermione's doubtful faces, and grinned. "Quite understandable," he said, as Harry shrugged apologetically. "It seems we shall need Snape's evidence after all…"

And with that, he had waded into the fight and separated the two men, gripping each by their collar like a pair of dogs. As Snape snarled at him, Harry decided that analogy wasn't too far off. He wondered vaguely what kind of animal Snape might be if he ever took it into his head to become an Animagus. Probably a snake, he thought.

"If you could both kindly stop that for a moment," Lupin was saying, as Sirius and Snape hung from their collars, still trying to swing at each other, "Then we might be able to help Ron before something intractable happens to him. What were you going to suggest, Severus?"

The nasty-looking glint returned to Snape's eye. It was the kind of look Harry recognised from many of his Potions lessons: the kind of look he got just prior to giving out detentions.

"Just a brief experiment," he said smoothly. "I'm sure you know what I'm talking about."

Sirius attempted another punch in his direction, but unfortunately ended up hitting Lupin instead. Snape said nothing, and fiddled with the silver buttons on his robes darkly. Lupin nodded, and let go of the two men.

"Fine," he said. "Harry – why don't you and Hermione take Ron into the next room, and put him in the bed there? We'll be through in a moment."

Curious, but doing as Lupin suggested, Harry put an arm underneath Ron's shoulder, and Hermione did the same on the other side. Together, they hauled him upright off the table and into a standing position. His knees gave way; his head lolling onto Hermione's shoulder, Ron's limp body was carried off slowly into the next room. Harry and Hermione deposited him gently on the bed, and then sat down next to each other.

"What do you think all that was about?" asked Hermione.

Harry shrugged. "I don't know," he said. "But Sirius didn't look too happy, did he? I wonder how long they'll be…"

As it happened, they were not long at all. Harry had barely finished talking when they re-emerged from the kitchen, Snape in front, still playing with his silver buttons. Both Sirius and Lupin, Harry noticed, looked extremely pale.

"I hope your experiment convinced you?" Sirius was saying, bitterly.

To Harry's surprise, Snape merely nodded, and made no attempt to make one of his usual comments.

"Now," he said briskly. "Let's see to Weasley."

Harry and Hermione were ushered out by Snape, who sent them to look for ingredients for his potion. Sirius accompanied them.

"Will Ron be all right?" asked Harry, pulling a face as he picked up a handful of slugs from underneath the shadow of a gorse bush. Sirius shrugged.

"He should be," he said shortly. Harry got the impression that Sirius was still brooding over whatever it was that Snape had done to Lupin, and they finished searching for the rest of the ingredients in silence, returning to the little hut after two hours and giving Snape the slugs, three shed snake skins, eleven and a half minnows (Sirius had spent the better part of the time outside lying on his stomach wiggling his hand about in the stream) and two frogs that Hermione had been too squeamish to disembowel herself. Snape took them all wordlessly.

Ron, it seemed, was making a good recovery. Although still unconscious when Harry and the others had returned, he looked much healthier now, and more peaceful. Snape told them that he should wake up soon: after drinking the potion, he said, tossing the frog's liver into a simmering cauldron and wiping his hands on his robes, it would be a matter of hours before he was back on his feet. Harry and Hermione shared a heartfelt look of relief.

Harry still wasn't quite sure what to make of Snape's rather violent mood swings. As he had grown accustomed to nothing but difficulty with the Potions master over the last four years, he discovered, like Ron, that this sudden change of heart was intensely disturbing. One minute he would be the same old Snape they knew and – well, Harry wouldn't say loved, as such – but then the next he would be visibly trying to act pleasantly.

Harry decided that this 'nice' side of Snape only really emerged when he was talking to him, Ron or Hermione. The tension between Sirius was thick enough to be cut with a knife, and Snape also, it seemed, had not got around to forgiving Lupin for whatever it was he thought he'd done. Harry sighed. He didn't know what had happened back in the shack between the three men that had caused Sirius to get so angry with the professor, but he knew that it must have been something beyond the normal bickering. Oh well. Harry turned to look at Ron: his friend was still pale, but at least he was no longer blue; and, perhaps more importantly, he was most definitely still alive. Perhaps things were improving after all.

Ron woke up an hour later, just in time for the tea that Sirius had made. Harry, who had been sitting at the foot of his bed watching him, stared at him in concern as he raised a hand to his head and ran it through his hair experimentally.

"Yesss…" he hissed.

"Ron," began Harry, hoping with all his might that this wasn't another Brollachan he had to deal with.

At his voice, Ron suddenly stared at him, unblinkingly. "Harry!" he said. Then: "The Selkie! The – what happened? It wasn't a Selkie, Harry, it was a horrible thing, a – a – "

"A Brollachan," supplied Harry helpfully.

"A what? What happened to it?"

"Lupin killed it, I think. How are you?"

Ron sank back into his pillows and groaned. "Terrible," he said. "Horrible. I don't think eating all that Hubble gum was good for me…"

"You get indigestion if you eat too much gum," said Hermione, who had suddenly materialised out of nowhere and was standing there next to Ron, peering at him with concern plastered all over her face. "It gets stuck in your stomach. You aren't meant to eat it."

Ron nodded, glumly. "I realise that now," he said. "But what happened? What did you do after I – after I went in the stream?"

Harry considered, unsure of how much to tell him. "The Brollachan made itself look like you," he said. "We thought it was you, come back… only you were blue, and then you grew teeth, and then we realised it wasn't you after all and Lupin killed the Brollachan and we went and found you and brought you back here, and… well, here you are."

Ron looked confused. "OK…" he said.

"I'll get Snape," said Hermione, and hurried off. Ron's eyes widened.

"Why's she doing that?" he asked, panicking. "What have I done? Why…?"

"Because you need to drink this." Snape's oily voice drifted down to them. "Out of the way, Potter… this has some peculiar side-effects…"

Ron backed up against the headboard, gripping at his bed coverings with white-knuckled hands. He looked petrified. Harry, grinning with sheer relief that his best friend was back to normal, walked slowly out of the room with Hermione to the sound of Ron's protestations and what were possibly soothing noises coming from Snape. Harry's smile widened. He was glad he wasn't in Ron's shoes.