.

-O-

CHAPTER 1

The crackle of the fire in the Ravenclaw common room, combined with the low purr of the kitten in her lap, made it hard to concentrate on the words. Rose stroked her pet's yellow fur absentmindedly with one hand, holding up the book in the other, utterly determined to finish this chapter without nodding off. The footsteps that approached her blended in with the voices of the other students, the quiet scratching of quills and rustling of parchment, so she didn't notice her friend until he sat in the chair next to her and his hand reached to pet the kitten's head.

"So, you got a cat over the summer," he said.

Rose looked up and smiled at him. Lawrence Desrosiers was a tall, lanky blond, equal parts intelligence and sarcasm. One could hardly tell he was a foreigner most of the time—his English was as excellent as his well-coiffed hair—though on occasion, if he was excited or nervous, he had a tendency to slip into French.

"Oh, that's right, you didn't get to see much of him on the train," she said, remembering that the two of them had to spend the ride in the prefects compartment while the cat remained with her luggage. The kitten leaned into Larry's hand and purred, making her chuckle. "I think he likes you."

"I think I like him too," Larry said, a smile pulling on the corner of his mouth. "What's his name?"

"Fitz," Rose replied.

Larry's eyebrows immediately went up, his smile turning into more of a grin. "Fitz?" he repeated, amused.

"Ah, well, Curly came to visit me over the summer and... convinced me to get him," she said, rather sheepishly. Curran "Curly" Fitzherbert was extremely hard to say no to, partly because he was very persuasive, and partly because he was as stubborn as a mule when convinced he was right. "You know how he is."

Larry nodded. "Curly can convince the devil to go skiing." After a small pause, he added, "And it would probably be the best vacation of the devil's life."

The two Ravenclaws laughed.

"This was his birthday gift to me." Rose held up the book on pet care she was reading. "He thought a pet would do me some good. My parents weren't very happy, especially after the fourth vase he broke," she continued with a glance down at Fitz, stroking him affectionately. "He has so much energy." The kitten swiped at her hand playfully.

"Takes after his namesake," Larry said, trying not to laugh.

Rose chuckled. "He does."

"Listen, he is terribly cute and all, but we do need to get going," Larry said, scratching Fitz behind the ears. "Lupin is taking this whole Head Boy thing very seriously."

"Oh, right. Prefect rounds," Rose remembered. "I'll just leave this in my room and be down in a bit."

He nodded. "I'll wait for you by the door."

Rose picked up her wayward kitten and her book, and then headed up to the girls' dormitories.

-O-

"So, how was India?" she asked as the two of them rounded a corner on the third floor fifteen minutes later.

"Oh, it was great. I got to ride an elephant."

Rose's eyes grew wide as tea plates. "An elephant? Really? I've never seen one before. What was that like? Did you measure its ears? I read they're wider than a full arm's length."

Larry laughed. "I didn't whip out measuring tape and go for the ears, no. The ride made me kind of sick, actually." He grimaced at the memory. "So much worse than flying carpets."

"Are flying carpets smoother?"

"Yeah. You've never been on one?" he said, surprised. She shook her head. "I'll buy you one for Christmas, then. We can ride it around Hogwarts."

Now it was her turn to laugh. "Larry, flying carpets are illegal here. They're classified as Muggle objects."

His eyebrows rose. "Really? Well, you'll just have to come visit me in France, then. The grounds of my father's estate are beautiful from a bird eye's view."

Rose's eyes wandered to the ground. "I'm sure they are, and I would love to see them... But I'm not sure my father would let me travel abroad." Or anywhere.

He frowned. "They can't keep you in that manor forever."

She looked away. "I meant to ask you, by the way, if you've seen Moe today? I waited for him in the library for our Arithmancy study session, but he never showed up. That's not like him." Rose was usually the one to help other people with their studies, but things were getting difficult with the high number of NEWTs she was taking. Moses North was brilliant with numbers, and had offered to help when he saw the pressure she was under.

"Oh, uh, about that..." Larry eyed her wearily. "Don't freak out, but he's actually in the Hospital Wing at the moment."

Her head snapped to look at him. "Hospital Wing?!" she exclaimed, freaking out. "Is he okay?"

"He is, he is," Larry said hastily. "They're just keeping him overnight. You know, hospital rules."

"Why? What happened?" Rose insisted.

"It wasn't that serious," he said. "Just one of his experiments went slightly wrong."

"Slightly?" Rose interrupted, stopping in her tracks. "He's in a hospital!"

"It's okay, Curly was there," Larry repeated reassuringly, coming to a stop as well and turning to face her. "A spell backfired, that's all."

"Curly is not a Healer yet," Rose said grumpily, though the fear subsided — she had full confidence in Curly's magical abilities. "How bad is it? Have you seen him?"

Larry nodded. "A few burns, nothing major. He's fine. A bit roughed up, maybe, but he'll live." Rose grimaced at that. "He's been through worse," Larry reminded her. "And he's tough; he can take it."

"That doesn't make this okay," she countered sourly. Rose was aware that she was a bit coddling towards Moses, a boy who was nearly two heads taller than her and almost twice as broad, but could not help herself. She looked out the window, eyes soaring to the Hospital Wing. The lights were on inside. Was Moe there, she wondered? Was he that shadow on the left?

"Hey." Larry's voice brought her back to the here and now. "Is that a student?"

Rose followed his gaze down to the courtyard. A light crawled across the grounds, bobbing up and down as it went along.

"I don't know," she said slowly. "This doesn't look like wand light..." She turned to look at him. "And why is it green?"

His eyes remained on the strange glow. "Only one way to find out," he said. "Come on."

"Wait!" Rose grabbed a hold of his sleeve. "Shouldn't we tell the teachers? I mean... what if it's not a student?"

Larry looked at her. "By the time we do, they'll get away. And besides that, we are prefects, Rose, this is why we have rounds in the first place." He hesitated for a moment, then said, "If you're scared... you can wait for me here? I'll be back quickly."

She shook her head firmly. "If you're going — I'm going."

He gave her a reassuring smile. "I'm sure it's just someone sneaking out of bed after curfew. Hogwarts is the safest place in the world, right?"

She nodded, still unsure. "Right." Besides, Larry was with her. What could go wrong? "Let's go."

-O-

The chilly September breeze whipped blonde locks behind her shoulders as Rose followed Larry out the big oak door of the school. The distant light was now gleaming behind a window in Greenhouse Two. She had a very bad feeling about this but kept up with her friend, hand gripping the end of her wand. As they approached, he slowed their pace down, taking care to step as lightly as possible.

When they made it to the door, Rose pulled on his sleeve and whispered, "Look." It was slightly ajar.

The two teens exchanged a look, and Larry reached for the door, pushing it gently. Rose went in after him, the feeling of dread intensifying with each step. At the very bottom of the Greenhouse, where Professor Longbottom's office was located, another door lay open, flooding the room with soft green light.

"They managed to get into a professor's office…" Larry muttered. Rose felt very uneasy.

The two prefects slipped inside and crept silently by a row of huge pots, bending down to hide in the plants. The light was now stationary, and the low rustling of paper sounded in the empty Greenhouse. Rose peeked between the foliage.

The intruder's back was turned to her, and their lantern—the source of the odd green light—was perched on top of Professor Longbottom's desk. They were wearing a long hooded cloak, dark blue in colour, which moved as they opened drawers and rifled through papers. Fear rose up in Rose's chest — blue cloaks were definitely not part of the school uniform. She looked to Larry, unsure of what to do.

"On three," he mouthed, holding up his wand. She nodded. "One." He stood up. "Tw—Ugh!" A Venomous Tentacula vine, which had silently wrapped around them, jerked them back abruptly, effectively squeezing the air out of their lungs.

"Diffindo!" Rose croaked. The vine fell to the ground, and so did she, crumpling to her knees. Larry reached for her arm and helped her up, but it was too late — the cloaked figure had spotted them.

It turned around sharply, its arm bumping into Professor Longbottom's beloved Mimbulus Mimbletonia, which stood on the far right end of the desk. The cactus immediately started oozing stinksap over the piece of parchment they were holding, evoking a disgusted sound as they dropped it and reached inside a brown satchel hanging from their shoulder. There was a hiss, a low metallic sound as something rolled onto the floor, and with a flourish of the cloak, the figure ducked under the desk.

Then came the explosion.

A white flash blinded Rose completely. Her body was thrown back by the impact, colliding with the clay pots behind her, which broke under her weight. A high-pitched noise drowned out everything else, accompanied by a sharp, pulsating pain in her head. For a few minutes all she could do was lay in the dirt, waiting for the world to take solid shape again. Something moved below her and crawled up her leg, but with another smudged flash of light, it slithered off. Through the noise, she could hear a distant, muffled voice calling for her. Rose forced her wandering consciousness to focus. A hand gripped her shoulder, shaking it gently.

"Rose! Rose, say something, are you okay?"

She pushed herself up into a sitting position, her head spinning like a top. "Larry?" she muttered.

A figure loomed over her, smudged and out of focus. "Come on." His arm wrapped around her and pulled her up. "We need to get you out of here."

Rose staggered and leaned on him, her kneecaps about as firm as butter. Broken glass crunched under her shoes as they made their way across the oddly bright greenhouse and over a broken wall. The cold air helped her concentrate, and she noticed it was easier to breathe. Looking over her shoulder, Rose finally registered that Professor Longbottom's office was on fire.

Once they were far enough away, Larry set her back on the ground. "Are you hurt?" he asked, moving a few locks of hair from her face.

"I don't think so... Just dizzy," she replied. "You?"

"Other than the broken eardrums and the burnt retinas?" he said dryly, but then added in a more serious tone, "I'm fine."

Rose quickly inspected him for injuries. "Your sleeve is torn," she noted. The rush of panic did not help her spinning head as her eyes snapped to his, wide with concern. "And there's blood."

"The Tentacula," he said dismissively. "We crashed into it. It did not take it well." Rose frowned at his tone and rolled up the sleeve. There were long, red scratches along his arm, but nothing too serious. "I'm lucky I didn't get hit when the glass exploded," he added.

They both turned towards the Greenhouse. Tall flames danced inside the room as various leaves, vines and other appendages flailed in the inferno, throwing long shadows on the ground. Thick, black smoke rose from the broken glass walls, towering up into the dark sky. One of Professor Longbottom's purple Umbrella Flowers fell from the ceiling and straight into the burning blaze.

Larry sprang to his feet. "We have to put out the fire!"

"Wait, Larry, it's dangerous!" Rose said.

"We can't just let the whole Greenhouse burn! All the plants will die!" Without waiting for her, Larry sprinted towards the fire, whipping out his wand. "Aguamenti!" A stream of water erupted from the tip, dousing some of the desk. But it was not enough.

Rose stood up on shaky knees and took out her wand. Water. She had to make water. "Agua..." she whispered weakly. "Agua... Agua..." She knew the spell. She had mastered it when her studies required it, but she had never, ever used it outside the classroom. "Agua..." Her fingers gripped the wand so hard it hurt. The more she tried to picture water, the higher fear clawed up her chest, suffocating her. She had to help Larry. She had to help him... but she couldn't.

"I'll go get the teachers!" Rose turned round and ran towards the castle like the coward she was.

She still felt weak, but her legs carried her faster and faster, first to the Entrance Hall, then up the marble staircase and all the way to the third floor, the closest teacher's rooms. When she reached the Defence Against the Dark Arts office, she stopped to catch her breath. As she expected, there was faint music coming from inside.

Rose banged against the door. "Professor Smith!"

There was a sound of a needle scratching to a halt, and the music stopped. Unnaturally quick footsteps padded over the floor, and the door swung open.

"Rose!" Professor Smith exclaimed in his thick southern American accent, taking the Blood-Flavoured lollipop out of his mouth. "Is everythin' okay?"

"There's a fire... In the Greenhouse..." Rose wheezed in-between breaths. "Professor… Longbottom's… office."

Professor Smith's red eyes instantly grew serious and snapped to the window behind her, where a pillar of black smoke was rising in the distance. "Poppy!" he said, turning around. With a hurried shuffle, his House Elf came to his side. "Go wake up Professor McGonagall. Tell her there's a fire in the greenhouses. Then wake up Professors Clearwater and Longbottom, in that order, and tell them the same."

"Yes, Sir!" Poppy squeaked, winking out of view.

Professor Smith threw the lollipop in the rubbish and closed the door.

-O-

Rose's lungs felt like they might collapse at any moment, but she still ran, forcing her legs to move. When the Greenhouse was finally in view, her eyes immediately widened in panic, because Larry was nowhere to be seen. As she approached, she heard him cough and saw in the firelight his silhouette bumbling inside.

"Larry!" Rose leapt straight into the smoke.

"Rose, don't!" Professor Smith called after her, but she didn't listen.

The black smoke inside was so thick her eyes immediately watered, making it impossible to see. Luckily, Larry's cough was still audible over the crackling of the fire. She found him hunched over the desk, one arm coiled around Professor Longbottom's Mimbulus Mimbletonia. Rose wrapped an arm under his and pulled him up, stumbling towards the exit.

When they made it to a safe distance, she stopped, and they both coughed for a few minutes, clearing their lungs from the toxic air.

"Why were you in there?" she said hoarsely, looking him over. His face was flushed and covered in cinder, but there weren't any obvious burns.

"Professor Longbottom's Mimbletonia," he replied, coughing some more. "I couldn't put out the fire… It was going to burn."

"You went in there for a cactus?" Rose exclaimed incredulously. "What is wrong with you? And if the ceiling had collapsed? If the fire spread too quickly? What were you thinking?!" He didn't answer, but she didn't need him to. As level-headed as he normally was, she knew that plants were a special matter to him. Her eyes softened. "Don't pull stunts like that," she said quietly. "You scared me half to death."

Larry held her gaze for a moment, before replying in the same muted voice. "I'm sorry."

"Brian!"

Rose and Larry turned to look at the figures of Professors McGonagall, Clearwater and Longbottom, quickly approaching from the castle. The fire raging in the greenhouse had almost completely died down. While Rose was busy hauling Larry outside, Professor Smith had used a wind funnel spell to suck the oxygen out of the room instead of trying to put it out with water.

"Brian!" Professor McGonagall repeated breathlessly. "What is going on? Why is there a fire in Professor Longbottom's office?"

"Ah, Minerva," Professor Smith replied lightly, flashing her a fangy grin. "I was just putting the finishing touches on Neville's new office. I think I have a real flair for decoratin', wouldn't you say?"

"Do not crack jokes at a time like this!" McGonagall scolded him. "What happened here?"

"Waltz! Desrosiers!" Professor Clearwater said, running over to the two students. "Are you both okay?" They nodded. She gripped each of their shoulders. "Why were you outside the castle? Did you see who set the fire?"

"I think we'd all want to hear 'bout that," Professor Smith said, approaching with the Headmistress. Longbottom, who was inspecting the damage to his office, tore himself away to join them.

"Well, we…" Rose started hesitantly, shooting a look at Larry. "We were doing our prefect rounds, and we saw a light through the window. We thought it was students sneaking out of bed, so… we came to investigate."

"And?" Clearwater prompted. "What did you see?"

"There was someone," Larry continued, "going through Professor Longbottom's desk. We couldn't see who it was, they were wearing a hood." The teachers exchanged worried glances. "We tried to stop them, but… the Venomous Tentacula got us," Larry admitted.

Clearwater shot Longbottom a glare.

"My office is not meant for students to wander in," he said defensively.

"And yet, two of mine almost died because of the inappropriately dangerous plants you keep in there!" she returned angrily.

"My plants," Longbottom said hotly, "are locked behind spells! And they…" His voice softened a bit as he glanced at the charred remnants of his office. "They're mostly gone now." The sorrow in his voice was heartbreaking.

"I'm sorry, buddy," Smith said, patting his shoulder.

"Ah… Professor?" Larry took a step towards Longbottom. "I… I did save one." He held up the cactus.

Professor Longbottom's eyes moved to the plant, and Rose could swear she could see tears in them.

"My Mimbulus Mimbletonia," Longbottom said gently, taking the pot as if it were a wounded animal. "How…?" He looked to Larry, barely containing himself. "Thank you, Larry." He raised his hand to pet it, and the cactus made an odd crooning sound. "Fifty points to Ravenclaw."

Professor McGonagall raised an eyebrow. "Fifty? For saving a cactus?"

Longbottom threw her an incredulous look, making Smith try to stifle snort. "For preserving a valuable specimen! And," his gaze moved to Larry, his mouth stretching into a grateful smile, "a precious personal possession."

Larry happily returned the smile, blushing slightly.

"I think we can all agree that some points are merited here," Smith said, glancing at Rose. "Ten points to Miss Waltz for the speedy warning."

"Not that I want to stop you from giving my House more points," Clearwater cut in, "but these two need to get some sleep. Now," she turned towards the prefects, "is there anything more you want to add before I send you off to bed?"

Rose shook her head, but Larry nodded.

"Oh, yes! I almost forgot." He rummaged through his robes, producing an odd metal cylinder. "I tripped on this. I think the cloaked person dropped it."

Professor Clearwater's face suddenly gained a worried look, reflected by the other teachers. "Junk," she declared firmly, growing serious.

"But, Professor…"

"I'll get rid of it," she said, snatching it from Larry's hand. "Now, if that's everything…?"

"Yes," McGonagall said. "Take these two to Ravenclaw Tower. They have earned some rest."

Professor Clearwater gathered them up and led them towards the castle, while the other teachers returned their attention to the burned office. If she had to be honest, Rose was happy to be heading up to bed — she was so tired it was a wonder she hadn't fallen asleep on her feet yet. The trek up to the Tower only served to strengthen that feeling, leaving her out of breath again. She didn't even pay attention to the knocker's riddle, or the answer Clearwater gave.

It was only after the teacher left and Larry was about to head up that she spoke again. "Larry?" He stopped halfway up the staircase. "I…" She looked away in shame. "I'm sorry that I left. When you were trying to put out the fire."

He stared at her in confusion. "You went to get Smith, didn't you? It's not like you were drinking tea with the House Elves."

She shook her head. "But I should have stayed with you. I should have helped you, I just…" Her voice grew quieter. "I was too scared."

Larry came back down the stairs. "From the fire?"

Rose shook her head again, and her gaze finally met his. "From the water."

His eyes widened in realisation. "Water! I'd forgotten… Rose, I'm so sorry. I wouldn't' have… I would never ask you to…"

"You were trying to save the greenhouse," she interrupted. "And I wanted to help, I really did, but… I couldn't. So I went to get the teachers instead."

He reached for her hand. "It was the right thing to do. The fire was burning too intensely, I just wanted to save the plants… You were right, I don't know what I was thinking. I should have been smarter about this." His fingers gave hers a light squeeze. "Telling the teachers was smart."

His words made her feel better, and she gave him a slight smile. "I guess… Did it seem odd to you that they wanted to get rid of the cylinder? I mean, it was a huge clue, and now we'll never know what it was."

"Well." Larry grinned. "I don't really like the sound of the word 'never'." He let go of her and reached into his robes, pulling out the strange object. "How about 'now'?"

Rose gasped and took the cylinder in her hands. "How did you get this? I thought Clearwater had it."

"She did," he said. "But I don't like it when people take things away from me for no reason. So I took it back."

Rose shot him a reprimanding look, but her attention quickly returned to the object. It was black, seemingly made of metal, with holes spaced out through it in equal intervals. "Do you know what it is?"

He shook his head. "No idea. Do you?"

"No…" she drawled thoughtfully, turning it in her hands. "But I can at least find out what metal this is. Do you mind if I keep it overnight?"

"No," he said, "but get some rest tonight. Mystery-solving can wait until morning."

Rose was about to protest, but she could feel a yawn coming. "Good point. See you tomorrow?"

Larry nodded. "Tomorrow. Goodnight, Rose."

"Goodnight."

And with that they both headed up to their respective dormitories for some way overdue sleep.