After finding the ominous letter on Artemis' bed, the Hufflepuff girls forgot all about Merula Snyde and the Frog Choir. All they could talk about was the note, what it might mean, and who might have sent it.

"What sort of friend doesn't put their name at the end of a letter?" Tonks asked. "That's well dodgy, if you ask me."

"Perhaps it was Professor Dumbledore," said Penny. "He might not want to put his name on the letter, in case it looked like favouritism."

"Yeah, because Dumbledore never shows any favouritism, ever," scoffed Tonks, and she screwed up her face, and turned into the Headmaster. "Well done, Artemis, you've broken every school rule under the sun, here's a million house points..."

Artemis grinned and shook her head as Tonks' face became more Tonks-like again.

"I'm more concerned about this 'group' that you've apparently caught the attention of," Rowan muttered darkly. "I mean, we still haven't figured out who this 'R' person is that was threatening Ben last year, and now we have a whole other group of people to worry about."

"The letter didn't say to be worried about them, it told me to be courageous."

"It also said to be careful, Artemis," Rowan sighed. "Why don't you talk to Bill Weasley about it?"

When Artemis found Bill leaving the library the next day, he said much the same as Rowan.

"This is all very worrying, Artemis," he said, frowning as his eyes scanned the note. "You say there was no clue as to who the note had come from?"

"No. Penny thinks it might be from Professor Dumbledore, but I'm not sure. He's off looking for that Curse-Breaker, anyway."

"Hang on," said Bill. "Dumbledore's looking for a Curse-Breaker? Where did you hear that?"

"Hagrid let it slip."

"The teachers really must be worried about the Cursed Vaults. I wonder which Curse-Breaker he's looking for."

"Well, whoever they are, they're not going to break any curses while they're not here," said Artemis. "So It looks like I'll be doing it myself."

"You're incorrigible, you are," Bill grinned, and he ruffled Artemis' hair with the hand not holding the note. "Are you sure that's a good idea? I mean, this is all a bit -"

"I'm sure," Artemis nodded. "I've got the keys to my brother's room now and everything, so the search is back on."

"Well, you let me know if you need anything, okay? I don't want to see you getting hurt."

Artemis smiled at Bill, struck by a sudden instinct to wrap both her arms around his waist. Before she had a chance to do so, however, she noticed that Bill's eyes had strayed towards a group of girls in his own year walking down the corridor, and the colour had risen in his cheeks.

"Bill, are you okay?" she asked him. "Who is that?"

"Oh, that's no one," his face getting pinker. "Well, no, it's not no one. It's Emily Tyler."

"Oh!" Artemis grinned from ear to ear and rose up onto her tiptoes, craning her neck to get a better view. "Is that the girl you like?"

"Artemis, stop looking at her," Bill hissed, and he pushed downards on Artemis' shoulders. "At least be subtle about it, for Merlin's sake!"

"Subtlety has never really been my style, Bill," she said, smirking mischievously. "Besides, don't you want her to know how you feel? She might like you back."

"I should be so lucky," Bill replied. "I was thinking about maybe asking her to go for a drink with me in the Three Broomsticks at the next Hogsmeade weekend. It's on Valentine's Day, after all."

"Why don't you?"

"Because, she is out of my league, Artemis," Bill shook his head. "I don't really fancy making a fool of myself in front of the coolest girl in my year."

"If you like, I could talk to her for you. Figure out if she might be interested? That way you'll know if it's worth asking her out," Artemis offered, and, seeing the look on Bill's face, she laughed. "Don't worry, I'll be subtle!"

Artemis decided to approach Emily Tyler the next day. Having promised to Bill that she wouldn't be too obvious about it, she planned on accidentally bumping into Emily somehow. She knew that the fifth years had their Ancient Runes class the lesson after she did, so the next day as she left the class she loitered in the corridor outside, waiting for Emily to walk past.

"Diffindo," she coughed, pointing her wand at the older girl's fashionable looking handbag as she approached the Ancient Runes classroom. The seam of the bag split apart, and its contents spilled out onto the hallway floor.

"Bugger!" Emily exclaimed, and she waved her friends ahead as she began to collect up her belongings. Artemis walked over to her.

"Here, let me help you," she said, picking up a flamingo feather quill. "That's such a shame. I was just thinking how nice your bag was."

"It was, and expensive too. I'll be writing a letter of complaint to the shop I bought it from. Hopefully they will give me something for free to apologise."

"Well, I can try and fix it for you. Reparo!" Artemis pointed her wand at the split seam, which closed back together instantly. Emily did not thank her. She smiled at the girl, and pretended to only just recognise her. "Oh, you're Emily Tyler, aren't you?"

"Yes. Why?"

"Oh, no reason, it's just that you're in the same year and house as my friend, Bill."

"Right," Emily looked Artemis in the eye for the first time. She was very pretty, as pretty as Penny, but without the sort of warm glow that Penny always seemed to radiate. "You're that weird little cursed girl that's always following Bill Weasley around like a lost puppy. Ariadne, isn't it?"

"It's Artemis, actually."

"Sure," Emily smiled. It wasn't a sincere smile. It gave Artemis the impression of a fox about to play with a rabbit it had just caught. "What's your deal with Weasley, anyway? You just hanging around with him because he's good looking and you're hoping he'll eventually fancy you back?"

"Um, no," Artemis frowned. Whatever did Bill see in this girl? Still, she persevered. "But you think he's good looking, do you?"

"Well, I suppose he's not bad looking. And if you're like - what are you, twelve? - then he probably seems like the coolest boy at Hogwarts," Emily laughed cruelly. Artemis decided that she hated her even more than Merula. "But the thing is, he's a bit nerdy, and lanky, and he has no fashion sense, and no money. Let's be honest, I'm a luxury that Bill Weasley can definitely not afford."

Artemis' fist tightened around her wand, and she wished more than anything that she knew how to cast Bill's brother's Bat Bogey Hex.

"You can go away now, Ariadne," Emily flashed her another fake smile before flouncing off towards the classroom.

A red hot rage burned inside Artemis as she watched awful Emily walk away from her. She pointed her wand at the girl's bag once more.

"Reducto," she whispered.

Emily Tyler's fashionable bag combusted, and scraps of fabric, pink quills, books, and ink flew across the corridor in every direction. Emily stared at the mess, open-mouthed.

"Oh dear, Emily," Artemis called out to her, widening her eyes and holding her wand behind her back. "Looks like money really is no guarantee of quality."

Artemis wasn't sure how to break the news to Bill that his crush wasn't as perfect as he thought, but she had other things to think about first. Now that she had Merula's key to her brother's room, she was itching to get inside and investigate. The day after her run-in with Emily Tyler, she met Tulip Karasu outside the Come-And-Go Room with the other key.

"Hello, Artemis Hexley," said Tulip, with a coy smile. "Ready to uncover your brother's secrets?"

"If there are any secrets left to uncover," Artemis replied. "Who knows what Merula helped herself to?"

"You shouldn't listen to Merula. I was here with her when she was searching. She didn't find anything."

Tulip handed Artemis the second key and she unlocked the double padlock. Together, the two girls entered Jacob's room. It was pitch black inside.

"Lumos!"

The tip of Artemis' wand lit up, casting a single beam of light in the room. In the shadows of the far corner, something moved. Artemis shone the light towards the movement and saw that it was not something, but someone.

A person was standing in the darkness, wearing a hooded cloak that cast their face in shadow. The figure in the shadows lifted its hood to reveal its identity, and Artemis felt her heart thudding, fast.

The face beneath the hood was like no other she had ever seen. The skin was deathly pale, the nose completely flattened with only slits for nostrils, and the eyes red and snakelike. Artemis desperately wanted to scream, to run, to fight, but found herself frozen to the spot, unable to do anything at all.

As she stared in horror, the face began to shift, to change. It was becoming less serpentine, and more human, but that didn't make it any less terrifying. As she recognised the dark-haired, hazel-eyed person standing in front of her, Artemis felt cold all over, and heart started to beat even faster. She could feel her own racing pulse everywhere, in her stomach, in her chest, in her throat, in her head.

"Artemis, it's not real," Tulip said from behind her. "It's a Boggart, it's just a Boggart!"

But Artemis could barely make sense of her words. Tulip must have realised that Artemis was petrified by her own fear, as she grabbed her by the elbow and pulled her from the room, slamming the door closed behind them.

"We will have to come back another time," Tulip said, placing the padlock back on the door. She turned to face Artemis. "Do you know the Boggart banishing spell?"

Artemis shook her head, still unable to speak.

"Okay," Tulip placed both of her hands on Artemis' shoulders. "So, here's what we are going to do. We are going to find out how to cast the banishing spell, and then, when we are ready, we will come back and sort out the Boggart. Okay?"

"F-fine," Artemis heard her voice wavering and realised that she was shaking. "I'll ask Bill to teach me. He's bound to know it. I have other things to talk to him about, anyway."

Artemis went straight to the library to find Bill, and found both of the Weasley brothers looking over various books, whilst a group of second year girls Artemis recognised from her own common room stared openly at Bill from the adjacent table.

"Merlin's pants, Artemis," said Bill's brother Charlie, putting down the copy of 'Survival Magic and Tracking Spells for the Field Magizoologist' that he had been reading, and standing up so she could take his seat. "What happened?"

Artemis sat in Charlie Weasley's vacant seat as he pulled over another chair for himself. In a voice that still trembled, she told them about the Boggart in her brother's room.

"Blimey," Bill put a protective arm around her shoulders as Charlie started to rummage in his brown leather satchel. "No wonder you look so shaken up."

"Yeah, it was pretty horrible," Artemis nodded. "I came here to ask you if you'd be able to teach me the Boggart banishing spell ready for next time."

"Next time?" Charlie looked up from his schoolbag and raised his eyebrows at her. "You're planning on going back?"

"Of course she is. Artemis always goes back to the scene of the crime," Bill said, giving her shoulder a gentle squeeze.

Charlie shrugged, pulled a bar of chocolate from his bag, and pushed it across the table towards Artemis.

"Thanks," said Artemis, taking the chocolate bar with a small but grateful smile. She turned back to Bill, who took his arm back. "So, will you teach me the spell?"

"Absolutely. You know I'm always happy to help my favourite Curse Breaker," Bill said in a hushed tone, as Madam Pince the librarian walked past. Artemis quickly hid the chocolate bar under the table. "Talking of helping each other out, did you manage to speak to Emily?"

"Um, yes," Artemis snapped off a small square of chocolate under the table and, checking that Madam Pince wasn't looking, offered it to Charlie. He shook his head, and she placed the square into her mouth. The sweetness of the chocolate made her feel less shivery immediately. "I'm afraid I don't think she'll be very keen on going on a date. I'm sorry."

"Oh, right," Bill seemed to put on a brave face. "Well, what did you make of her?"

"Honestly? I thought she was foul."

"See? It's not just me." Charlie said triumphantly, earning himself a dirty look from the librarian.

"You don't like her either?" Artemis whispered as Madam Pince skulked away.

"I've been telling Bill for ages that he'd be better off with, well, literally anyone else," Charlie folded his arms and rocked back on his chair legs, fixing his brother with a meaningful look. "But apparently he doesn't trust my advice when it comes to girls."

"That's because we both know your heart only beats for one thing, Charlie."

"What's that?" Artemis asked, slipping another piece of chocolate into her mouth and flicking her eyes between the two brothers like she watching a tennis match.

"Dragons," they said, in perfect unison.

Artemis sniggered, and Madam Pince shushed her.

"Charlie's right, Bill. Madam Pince would be more fun to go out with than Emily Tyler," Artemis said, once the librarian was once again out of earshot. "Have you ever even had a conversation with her?"

"Emily? Not really. Every time I try to talk to her I get so nervous. She's just so clever, and talented, and pretty -"

"Pretty horrible," muttered Charlie, reaching across the table and taking a square of chocolate from Artemis.

"- and popular and kind of, well, perfect," Bill continued, ignoring his brother. "She's like the Penny of our year."

"What?" Artemis exclaimed, incredulous. Madam Pince glared at her again, so she lowered her voice. "Bill, I've never met anyone less like Penny in my whole life. Penny's so popular because she's a lovely person and manages to make everyone she meets feel like they matter. Emily spoke to me like I was pondlife."

"Don't take it personally," said Charlie, popping another square of chocolate into his mouth. "She speaks to everyone like they're pondlife. Bill, why don't you have a go at talking to her for five minutes? You'll soon see what we mean."

"No talking!" the sharp voice of Madam Pince interrupted their conversation. Artemis turned to see the librarian's hawk-like face bearing down at her and Charlie. "And chocolate! Near the books! You, and you. Out!"

"Bill, you know we are only saying this because we care, right?" Artemis said, as she and Charlie quickly gathered their belongings and stood up to leave before Madam Pince really lost her rag. Bill made a non-committal noise in response and his gaze returned to the book in front of him. "We just want you to find someone who deserves you. Trust me, you could do a thousand times better than that Emily Tyler."

"Well done for trying," said Charlie, as he and Artemis walked out of the library. "Hopefully he'll actually listen to you."

"I just don't get it," Artemis said, throwing her arms in the air. "He's so clever, and he's being so stupid. Girls fall to pieces over him all the time, and out of all them he's picked that bloody Emily. Honestly, she is the worst person I've ever met, why on earth would he want to go out with her of all people, when pretty much every girl in the castle is queuing up just to speak to him?"

"I guess he likes the challenge," Charlie shrugged. "And to be honest, I don't think he really notices the girls that follow him around. He just assumes they're being friendly."

"Are you sure?" Artemis wrinkled her nose, and looked back through the door of the library to see a fourth year Slytherin girl talking to Bill with one hand on her hip and her chest thrust forward. "I mean, look at that. How can anyone be that oblivious to someone fancying them?"

"I really don't know, Artemis," said Charlie, shaking his head. "Anyway, I'd best be off."

"Why, where you going?"

"Just taking my broom out for a quick fly before it gets dark," he replied. Although she didn't know him well to tell for sure, Artemis could have sworn that there was something he wasn't telling her. "I'll see you around."

"Wait," she held the rest of his chocolate bar out to him. "Don't forget this."

"Keep it. It sounds like you'll be needing more than I will."

Artemis thanked Charlie, and he walked away with a shrug.

Despite his broken heart, Bill was more than obliging when it came to helping Artemis and Tulip learn the Boggart banishing spell. Having practised it, the girls returned to Jacob's room.

"Perhaps I ought to go in first," Tulip suggested, retrieving the keys from her pocket.

"No, it's fine. I can go," Artemis said, shaking her head. "I'd rather face my fears sooner than later."

"As noble as that is, Artemis Hexley," Tulip gave her a wry smile, "your Boggart took the form of You-Know-Who. I'd rather you didn't go in first."

"As long as you're sure."

"Certain. I mean, what could possibly be scarier for the both of us than The Dark Lord?"

Artemis followed Tulip into Jacob's room, and cast the wand-lighting charm again. In the shadows, the Boggart swirled into motion.

"Get behind me, Artemis," Tulip ordered her, and she stood behind her, shining her wandlight over her shoulder. The Boggart was becoming a person again, but this person was much shorter than the previous one. As the features became more distinct, Artemis made out a familiar pale, pointed face, and violet eyes.

"You betrayed me, Karasu," Boggart-Merula said in a voice that sounded distorted. Her violet eyes were glowing, and she was approaching Tulip slowly and menacingly. Tulip stiffened as she raised her wand, and the Boggart continued advancing on her. "You're a fraud. A liar. It's no wonder your parents sent you away."

"Tulip! Cast the spell!"

"You're alone, Karasu. You'll always be alone," Boggart-Merula snarled as she came ever-closer to Tulip.

"R-riddikulus!" Tulip said, her voice only faltering slightly. Boggart-Merula stopped walking towards them and recoiled. Artemis stepped out from behind Tulip and saw one of the greatest things she'd ever witnessed in her life.

The Boggart was still in the form of Merula Snyde, but was now dressed in the least Merula-ish outfit Artemis could have imagined: a pink frilly dress, with a sparkly cardigan buttoned up to her collarbone. She clapped her hands to her mouth as she laughed at the sight. Hearing her laughter, Boggart-Merula glared at her, then vanished in a puff of smoke.

"That was brilliant," Artemis said to Tulip, who looked deathly pale. Artemis led her over to the wall and sat her down so that she was leant against it. She pulled Charlie Weasley's half-eaten chocolate bar out of her pocket and handed it to her. "Here, have this. The sugar is good for the shock."

Tulip wordlessly took the chocolate and turned it over in her hands. Artemis knelt down next to her.

"Are you alright?" she asked. Tulip said nothing. "It's horrible, isn't it? I felt shivery all the way to the library after I saw the Boggart last time."

"Your Boggart was You-Know-Who, though," Tulip whispered. "Anyone would find that terrifying. I shouldn't feel this bad, not with it just being Merula."

"If you don't mind me asking, why are you so scared of her?"

"It's not so much her," Tulip started to rip away pieces of the chocolate wrapper. She still hadn't so much as taken a bite of the chocolate itself. "It's what she said. Just then as a Boggart, and in real life, too. You probably don't know this, but Merula and I used to be best friends."

"When?"

"In our second year at Hogwarts," Tulip didn't meet Artemis' eye. "See, Merula's parents are in Azkaban, so she's always been left to do whatever she wants. Whereas my parents are really strict. For me, Hogwarts was the first place I could ever just be myself and not have to stick to the rules all the time. Merula kind of embodied that for me, and I kind of hero-worshipped her all the way through our first year. When she asked me to help her find the Cursed Vaults, I jumped at the chance."

Artemis suddenly remembered the sight of Merula Snyde on the training grounds with a dark-haired girl almost as short as herself. She hadn't recognised Tulip at the time - having not seen her face - but now it seemed obvious, especially as now that she could see the crown of her head, she could see that the roots of Tulip's cherry red hair were jet black.

"Then what?" Artemis asked.

"Well, I got carried away. I started to find more clues before Merula did. And I started to think that maybe I'd be able to find the Vaults quicker by myself. So I covered everything up," Tulip inhaled deeply, and shook her head. "When Merula found out, she was livid. Said that I'd betrayed her, that I've only ever been out for myself, and that's why I'd always been by myself and not had any friends."

"I didn't really have any friends before I came to Hogwarts, either," Artemis told her. "I was just lucky to make good friends when I came here. You were unlucky that you made friends with Merula."

"She's not as bad as people say she is. And she's right, I did betray her. It's no wonder I'm so rubbish at making friends. I don't deserve to."

"That's not true. You've made friends with me, now," said Artemis, and she nudged Tulip gently with her elbow. "I mean, you and I have faced You-Know-Who and Merula together. Surely that's got to count for something."

Tulip gave her a half-hearted smile.

"I guess so, Artemis Hexley."

"And you know, my Boggart wasn't just You-Know-Who, either," Artemis told her. "When its face started changing, it turned into... something else. Someone else."

"I did wonder who that man was," Tulip said, quietly.

"It was my brother," Artemis said, and she chewed on her lower lip. "For some reason, that was when I became even more frightened."

"Why?"

"I... I don't know."

The two girls were silent for a moment. Artemis shook her head, clearing it of thoughts of Boggarts, and Jacob, and You-Know-Who. She placed a hand on Tulip's forearm before standing up.

"Right, I'm going to search this room," she pointed at the chocolate bar. "Eat that, and whenever you feel up to helping me you can join in."

Tulip nodded and finally bit into the chocolate. The colour immediately seemed to return to her cheeks. Artemis smiled at her new friend and started to look around the room. The room was littered with maps, scrolls, newspaper clippings. Nothing was in order.

"Did Merula make this mess?"

"No," Tulip shook her head as she stood up. "No, this is pretty much exactly as we found it. I think your brother must have been more interested in finding the Vaults than he was in tidying up after himself. Personally, I think the chaos is charming."

"It might be charming, but it isn't going to help us find anything," Artemis shone her wandlight into a half-open drawer. "Wait! A black quill!"

"What?"

"My brother used to transfigure anything he didn't want people reading into black quills," Artemis explained. "Reparifarge!"

The quill turned into a sheet of parchment with one jagged edge like it had been ripped out of a notebook.

"No wonder Merula and I couldn't find anything too interesting!" Tulip gasped. "We never thought to look for black quills. What does it say?"

"That last time the Vaults were tampered with there were more Boggarts in the library than anywhere else," Artemis read the scrawly black writing. "That's where Jacob thought the next Vault must be, in the library!"

"The library is massive. How will we know where to look?"

"We will just have to search the whole place. I'll ask Rowan to help. She spends more time in the library than anyone else I know."

"I'll help, too," Tulip said, then frowned. "If you don't mind me helping you, that is."

"Of course not. We're friends, remember?"