Disclaimer- I don't own it, I promise.

I always forget to say something here, and it looks like that rend is gonna continue, 'cause I can't remember what I was gonna say. Also, I had to make some edits because my full moon numbers were off.

Anyway...Enjoy! :)

They had barely set foot in the cool entrance hall when a voice rang out, "There you are, Potter-Weasley." Professor McGonagall was walking toward them, looking stern. "Weasley, you will be doing your detention tonight. Potter, you'll be doing yours next week."

"What're we doing, Professor?" asked Ron, nervously suppressing a burp.

"You will be polishing the silver in the trophy room with Mr. Filch," said Professor McGonagall. "And no magic, Weasley- elbow grease."

Ron gulped. Harry felt his stomach plunge. Was his punishment going to be equally terrible?

"And you, Potter, will be helping Professor Lupin capture a grindylow for his third-year classes tomorrow evening. He expressed that he might need some assistance, so naturally I offered your services. You'll meet him in here."

"A...a what?"

"A grindylow. Eight o'clock sharp tonight for you, Weasley, same time next Sunday, Potter."

Ron glared daggers at Harry until they were out of earshot of Professor McGonagall. "I get Filch and you get Lupin? Where's the fairness in that?"

"Oh, I don't know," said Hermione from behind them. "Grindylows live in the Black Lake, it must be very dangerous if Professor Lupin can't do it alone. At least you won't be in harm's way, Ron."

Ron scuffed his shoe against the floor angrily. "I'd rather be in harm's way with Lupin than anywhere with Filch."

Harry privately agreed, but he wasn't about to flaunt his relief in front of Ron. He wondered how you caught a grindylow, and why they were doing it tomorrow and not that night. He also wondered if grindylows were poisonous or what they were exactly. The afternoon melted away, and around eight Ron, still giving Harry surly looks, left the common room. Harry spent the evening in the common room with Hermione, watching Fred, George, and Lee Jordan succeed in growing differently colored mustaches.

He tried to stay up late for Ron, but ended up falling asleep long before Ron crept back into the dormitory. The next day Harry and Hermione were regaled with Ron's horror stories of cleaning with Filch, including how he'd belched slugs all over a Special Award for Services to the School award and how it had taken ages to get all the slime off. Harry, for his part, spent most of the day convincing Ron that going grindylow hunting with Lupin would be terrible, an activity that Hermione was all too eager to join.

In fact, by ten till eight that night the next week, Harry had managed to convince, not only Ron, but himself, that he was probably going to meet a grisly end at the bottom at the Black Lake. He was not comforted when Professor Lupin showed up with his robes hanging more loosely on him and even darker shadows under his eyes. He certainly didn't look up to fighting off the army of grindylows that Harry envisioned attacking them.

"Hello, Harry," said Lupin pleasantly as he walked in, carrying a large empty tank. There were the only ones in the hall, and his voice echoed strangely. "We'd best get moving; we're off to the Black Lake."

His heart sinking, Harry concentrated on what Lupin was saying as they walked outside and set off at a brisk pace towards the dark waters of the lake.

"Normally I'd order a grindylow for my classes through Diagon Alley, but they're fresh out and I don't trust Knockturn Alley to deliver the goods ever since they shortchanged a kneazle I ordered for a long-haired cat. You all right, Harry?" said Lupin, glancing at Harry, who was turning steadily more green.

"Er, yeah, I think so," he said. "Is this dangerous?"

"Dangerous? Yes, but not very. I'd normally be up to it on my own, but I've been feeling ill lately and thought it might be good to have an extra set of hands ready."

Harry doubted his particular set of hands would be much use, but he didn't think it would be polite to say so.

The sun was almost completely down by the time they reached the lake, which looked more ominous than usual. Far more ominous. Harry hoped Fred and George hadn't been tickling the giant squid lately.

Professor Lupin made towards a large blob, that, as Harry grew nearer to it, turned out to be a rickety old boat. It reminded Harry of the boat Uncle Vernon had forced him and the Dursleys into to try to get away from Harry's letters; this was not a comforting comparison.

"Good, Hagrid's left this here for us," said Lupin approvingly. "Well, climb in, Harry."

Harry clambered into the boat, hoping he didn't wake up the next day with splinters in his bottom. On the other hand, if his only injuries were splinters he would be able to count himself lucky.

Professor Lupin climbed into the boat, pointed his wand at the bottom of the boat and said, "Impervius!"

"There," he said, settling into the boat and putting the tank beside him. "Now the boat won't leak."

He started the boat with magic and set it off zooming into the middle of the lake. Harry shivered, glad he'd worn his cloak. Lupin was staring at the surface of the lake intently, and Harry wondered what he was looking for.

"Aha!" he said suddenly, and the boat stopped. "Here we are. Do you see these weeds, Harry?"

Harry peered over the edge of the boat and nodded.

"Good. Grindylows like to nest in thick weeds, which is why the Black Lake is such a good place for them. They usually don't get so near the surface of the water, but the population here is such that they're forced to, because the merpeople don't like them too close to their crops."

Harry sincerely hoped he didn't see a mermaid down there.

"Now, I'm going to send a spell down there that should send at least one of them up the surface. It'll grab at the boat and cling to it, and when it does that I need you to grab its hand- its entire hand, fingers and all. That's very important, getting the entire hand. You can't let them get your hand, because it'll try to drag you under, and it would succeed too."

Harry looked at Professor Lupin in horror. "Drag me under?"

Lupin smiled. "Don't worry, I'll be able to get you back up, but I'm not strong enough right now to fight with the grindylow's initial strength. That's why I need you here, Harry."

"Okay," said Harry, feeling like he might vomit.

"A grindylow's fingers are strong but brittle. Once you have one of their hands it will try to get you to let go, and that's when you get the other one. Hold it out of the water and I'll take it from there."

"Ah," said Harry.

"Ready?"

Professor Lupin met his eyes, looking concerned. The boat tipped to the left a little, and his hand shot out to grab the tank from sliding.

"Harry, nothing will happen to you. Together we're more than a match for a grindylow. It'll only take a minute, I promise. Do you understand?"

"Yeah, I do," he said, finding that he trusted Professor Lupin and his tired smile.

"Three..." said Lupin, firmly holding his an inch into the water. "Two...one! Relashio!"

A jet of what looked like boiling water shot into the weeds, and Harry saw several sickly green creatures barrel out of the weeds. Most of them went under or away from the boat, but two grindylows surfaced and latched onto the side of the boat, causing it to sway dangerously.

"Go, Harry!" yelled Lupin, and Harry reached for the grindylow's long, spindly fingers, pulling his hand away when the grindylow bared its green teeth and made a grab for him. He pretended the grindylow's hand was a Snitch and snatched the grindylow's hand, making sure to get its fingers in his grip. The grindylow's hand was wet and slimy, but he didn't seem to be able to put his fingers out of Harry's grip.

"Now the other one," said Lupin quickly, his wand trained on the grindylow. "Get his other hand, Harry."

Harry waited for the grindylow's hand to get near him and grabbed it, cursing under his breath when it slipped out of his grasp. He tried again and yelled trimpuhantly when he got it, lifting the surprisingly light grindylow out of the water. Professor Lupin grabbed its arms and together they forced it into the tank.

"Aguamenti," said Lupin cheerily, filling the tank with water as the grindylow pulled faces and glared at them. He detached the other grindylow from the boat and collected some weeds from the lake with magic, putting them in with the grindylow. He set the boat off for the shore and sat back.

"I'll put him back in the lake after our lesson," said Lupin, pushing his graying hair out of his eyes. "Well done, Harry, well done! I don't expect my third-years to do as well as you just did, and they won't be in the middle of the Black Lake after dark."

Harry grinned before remembering he was supposed to be in detention. "Thanks, Professor Lupin."

"Just giving credit where credit is due. Now, it's about nine-thirty, isn't it? Sorry to keep you up when you've got class tomorrow, but I couldn't have done this any other night."

Harry thought of Hagrid and his wink when he'd said "paperwork" and wondered what it had been that he'd actually been doing.

"It is detention," said Harry cautiously. "I suppose I deserve it."

Lupin shook his head, still smiling. "I remember one time when F-Mr. Filch kept us up all night scrubbing floors. We most certainly didn't think we deserved that."

Harry looked at Professor Lupin in surprise, who laughed.

"It's always strange to imagine your teachers have lives, isn't it? I'm was a bit of a troublemaker at Hogwarts, although..." Lupin paused, hesitating. "...although my friends were worse."

Lupin had a strange look on his face, so Harry wasn't sure if he should be asking as he said, "Who were your friends?"

"A boy named Peter...he's dead now and...and your father, Harry. James was one of my closest friends."

Harry's mouth opened in shock. "My father? You knew my father?"

Lupin looked paler than usual as he said, "Yes, I did. We were great friends at Hogwarts. Like I said, he had a propensity for getting into trouble."

"How much trouble?" asked Harry eagerly.

"I think it was be correct if I compared us to the Weasley twins," said Lupin, smiling again, although it seemed somewhat strained. "They seem to be living up to our shoes."

"Wow," marveled Harry. "I never knew."

This last sentence had an unexpected effect on Lupin; he turned away form Harry until the boat reached the shore. Harry wobbled on rubbery legs for a few steps as Professor Lupin hoisted the grindylow's tank onto his shoulder, perfectly cheerful again.

"Back up to the castle, then," said Lupin as Harry got his legs back. "I'll walk you up to your common room in case we run into anyone, come on."

Harry followed Professor Lupin back up to the castle, exhilarated by his performance with the grindylow and subsequent praise and excited that he'd learned something new about his father.

They had stopped at Professor Lupin's classroom on the way to the common room to drop off the grindylow when Harry heard a hissing voice around him. He stopped in his tracks, looking at Lupin, who didn't seem to have noticed anything.

"Kill...must...kill...must find and...kill..."

Harry's mouth dropped open and he ran to follow the voice. Behind him, he heard Professor Lupin shout after him.

"Find...kill..."

He turned the corner, but there was no one there; wild with panic, he turned around to see Professor Lupin standing right behind him. He bent slightly so he could look into Harry's eyes.

"Harry, are you all right?"

"Didn't you hear it?" said Harry desperately. "The voice?"

"No," replied Lupin earnestly. "I didn't. What did it sound like?

"It was hissing...it was saying it wanted to kill..."

Professor Lupin looked alarmed, and Harry realized he really hadn't heard it.

"You don't think I'm making it up, do you?" he added hurriedly. "I'm not, I promise!"

"No, I believe you, Harry," said Lupin, his voice tight. He gripped Harry's shoulder as if to make sure he was still there. "You said it wanted to kill?"

"Yeah, that's what I heard."

"I'll talk to Professor Dumbledore about it right away. We'd best get you off to bed; yes, that's safest, I think," he said, sounding distracted. He steered Harry towards Gryffindor tower, and Harry felt better with Professor Lupin right behind him, although his elation of the last few minutes had worn off.

Who would have thought he'd be safer on the Black Lake than in Hogwarts itself?

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