Y/N's POV

After Transfiguration, Harry stayed behind to ask McGonagall if he could go to Hogsmeade, as I predicted, she said no.

"There's always the feast," said Ron, in an effort to cheer Harry up, "you know, the Halloween feast, in the evening."

"Yeah," said Harry gloomily, "great."

Nothing anyone said made Harry feel any better about being left behind. I offered to forge Uncle Vernon's signature on the form, but since Harry had already told Professor McGonagall he hadn't had it signed, that was no good. Ron halfheartedly suggested the Invisibility Cloak, but Hermione stamped on that one, reminding Ron what Dumbledore had told them about the Dementors being able to see through them. Percy had what were possibly the worst words of comfort.

"They make a fuss about Hogsmeade, but I assure you, Harry, it's not all it's cracked up to be," he said seriously, "all right, the Sweetshop's rather good, and Zonko's Joke Shop's frankly dangerous, and yes, the Shrieking Shack's always worth a visit, but really, Harry, apart from that, you're not missing anything."

On Halloween morning, we all woke up with the rest and went down to breakfast.

"We'll bring you lots of sweets back from Honeydukes," I said to Harry, looking sorry for him.

"Don't worry about me," said Harry, "I'll see you at the feast. Have a good time."

He accompanied us to the entrance hall, where Filch, the caretaker, was standing inside the front doors, checking off names against a long list, peering suspiciously into every face, and making sure that no one was sneaking out who shouldn't be going. When he got to me he smiled evilly,

"Says here you're not allowed to go." he said.

I looked shocked. "My parents signed my form."

Filch stared at me, he didn't like me after everything I had done. "Well Professor McGonagall says you're not allowed to go."

As if on cue, McGonagall appeared, a solemn expression on her face. "I know you signed your form L/N, but due to certain issues, you cannot go."

"You mean Black?" I said plainly, McGonagall looked shocked but nodded.

"You may be able to go another time, if the circumstances are different," she said before walking off.

Looking crestfallen, I joined Harry and waved Hermione and Ron as they made their way down to Hogsmede.

"What do you want to do?" I asked Harry as we walked back into the school.

He shrugged. "I dunno."

We wandered towards the library, but halfway there we changed our minds, we didn't feel like working. We turned around and came face-to-face with Filch, who had obviously just seen off the last of the Hogsmeade visitors.

"What are you doing?" Filch snarled suspiciously.

"Nothing," I said truthfully.

"Nothing!" spat Filch. "A likely story! Sneaking around are you?"

I ignored him.

"Well, get back to your Common Room where you belong!" snapped Filch, and he stood glaring until we had passed out of sight.

But we didn't go back to the Common Room, we climbed a staircase, thinking vaguely of visiting the Owlery to see Hedwig and Grey, and was walking along another corridor when a voice from inside one of the rooms said. "Harry? Y/N?"

I looked back to see who had spoken and met Professor Lupin, looking out his office door.

"What are you doing?" said Lupin, though in a very different voice from Filch. "Where are Ron and Hermione?"

"Hogsmeade," I said.

"Ah." said Lupin. "Why don't you come in? I've just taken delivery of a Grindylow for our next lesson."

"A what?" said Harry.

We followed Lupin into his office. In the corner stood a very large tank of water. A sickly green creature with sharp little horns had its face pressed against the glass, pulling faces and flexing its long, spindly fingers.

"Water demon," said Lupin, surveying the Grindylow thoughtfully, "we shouldn't have much difficulty with him, not after the Kappas. The trick is to break its grip. You notice the abnormally long fingers? Strong, but very brittle."

The Grindylow bared its green teeth and then buried itself in a tangle of weeds in a corner.

"Cup of tea?" Lupin said, looking around for his kettle. "I was just thinking of making one."

"All right," said Harry awkwardly.

Lupin tapped the kettle with his wand and a blast of steam issued suddenly from the spout.

"Sit down," said Lupin, taking the lid off a dusty tin, "I've only got teabags, I'm afraid, but Y/N, I daresay you've had enough of tea leaves?"

I looked at him. Lupin's eyes were twinkling.

"How did you know about that?" I asked.

"Professor McGonagall told me," said Lupin, passing me and Harry a mug of tea, "you're not worried, are you?"

"No." I said blankly.

Then Harry spoke. "I never got a chance to face the Boggart."

Lupin looked at him. "Well, I wouldn't have let you face the Boggart in class, truth be told."

"Why not?" Harry said.

"Well," said Lupin, frowning slightly, "I assumed that if the Boggart faced you, it would assume the shape of Lord Voldemort."

I looked at Lupin, apart from me, Harry and Dumbledore, no one else I knew called Voldemort by his name.

"Clearly, I was wrong," said Lupin, reading the expression on Harry's face, "but I didn't think it a good idea for Lord Voldemort to materialise in the room. I imagined that people would panic. Although...it backfired anyways..."

He looked at me briefly but I looked down.

"I didn't think of Voldemort," said Harry honestly, "I-I remembered those Dementors."

"I see," said Lupin thoughtfully, "well , I'm impressed."

He smiled slightly at the look of surprise on Harry's face. "That suggests that what you fear most of all is...fear. Very wise, Harry."

None of us spoke, me and Harry instead took sips out our teacup.

"So you've been thinking that I didn't believe you capable of fighting the Boggart?" said Lupin, to Harry.

"Well...yeah." said Harry. "Professor Lupin, you know the Dementors-"

He was interrupted by a knock on the door.

"Come in," called Lupin.

The door opened, and in came Snape. He was carrying a goblet, which was smoking faintly, and stopped at the sight of me and Harry, his eyes narrowing.

"Ah, Severus," said Lupin, smiling, "thanks very much. Could you leave it here on the desk for me?"

Snape set down the smoking goblet, his eyes wandering between me, Harry and Lupin.

"I was just showing them my Grindylow," said Lupin pleasantly, pointing at the tank.

"Fascinating," said Snape, without looking at it, "you should drink that directly, Lupin."

"Yes, Yes, I will," said Lupin.

"I made an entire cauldronful," Snape continued, "if you need more."

"I should probably have some again tomorrow. Thanks very much, Severus."

"Not at all," said Snape. He then backed out of the room, unsmiling and watchful.

I looked curiously at the goblet. Lupin smiled.

"Professor Snape has very kindly concocted a Potion for me," he said, "I have never been much of a Potion-brewer and this one is particularly complex."

He picked up the goblet and sniffed it. "Pity sugar makes it useless," he added, taking a sip and shuddering.

"Why-?" Harry began. Lupin looked at him and answered the unfinished question.

"I've been feeling a bit off-colour," he said, "this Potion is the only thing that helps. I am very lucky to be working alongside Professor Snape, there aren't many wizards who are up to making it."

Professor Lupin took another sip, I could tell Harry had a crazy urge to knock the goblet out of his hands.

I was taking in everything that Lupin had said and I only came to one far-fetched conclusion.

Professor Lupin was a werewolf.