London in August was hot and humid. Artemis Hexley and her loyal marmalade-coloured cat Fergus had just returned to her home in Lovelace Crescent after three weeks out of the city: one week staying at her best friend Rowan's family's tree farm, and another two with her great-Aunt and Uncle at their home in Dorset. Having spent the summer climbing trees and reading books with Rowan, cuddling Kneazles with her aunt and searching for murtlaps along the coast with her uncle, she was not looking forward to spending the remainder of the summer cooped up in the silent narrow house that backed onto the canal.

"You have letters waiting for you," her mother informed her, shortly after her arrival and a typically tense greeting. "I left them next to the fireplace."

Delighted by the prospect of receiving post from her schoolfriends, Artemis skidded across the stone floors of the hallway to living room. She found a parcel, four letters and a postcard waiting for her next to the fireplace.

The parcel contained a book about Transfiguration (Artemis' best subject at school), and had been sent by her best friend, Rowan, who was an avid reader. The postcard showed a picture of a seagull eating a pasty on a rock, and was written by her good friend Penny, who was on holiday in Cornwall with her extended family. Three of the letters came from her other friends: Bill, Tonks, and Ben, who had co-written his letter with Bill's brother Charlie, who had been staying with him and his family.

The final letter was from Artemis' school, Hogwarts School of Witchcraft and Wizardry. Artemis was about to enter her third year at Hogwarts, and the letter detailed her textbook list and confirmed the time and date of the train back to school from Kings Cross Station, just as the school had sent her the two years previously. This year, though, there was a second sheet of parchment in the envelope, which had never been included before.

"Mum," Artemis called out, reading the parchment. "Next year I'm allowed to start going to Hogsmeade village at weekends."

"That's nice," her mother called back.

"I need you to sign the permission slip," Artemis walked back from the living room to the study, where her mother's voice was coming from. "Will you?"

"Will I what?"

"Sign the permission slip. For school."

"Oh, right. Yes. Just leave it on the desk and I'll do it once I've finished with this."

"Thanks," Artemis said. "I've got my school list. I'm guessing you won't want to come and get everything with me?"

"Oh, Artemis, you know how much I hate Diagon Alley," her mother said, not looking up from her paperwork. "Maybe you could go with some of your friends? Maybe that Robyn girl you stayed with."

"Rowan."

"What?"

"Never mind," muttered Artemis. "I'll ask them. I'll leave my permission slip here on your desk. Please don't forget to sign it."

Artemis wrote back to Rowan, Penny, Tonks, Ben, and Bill, and arranged for them all to meet the following weekend in Diagon Alley to get their school supplies. At first, Artemis found it strange that the only one to not reply to her letter was Penny, who was normally the most sociable of all her friends. But, as Rowan reminded her in a second letter, not all of the relatives Penny was on holiday with knew she was a witch. It would probably be difficult for her to send a letter via owl mail without giving that away.

Rowan, being Rowan, had arrived early, and was already waiting at The Leaky Cauldron when Artemis arrived, reading her book in a quiet corner of the inn. After a spirited greeting, the two girls decided to look in the Magical Menagerie before they met their other friends at Florian Fortescue's ice cream stall.

They spent the best part of thirty minutes in the pet shop, eventually dragging themselves away from an adorable litter of kittens before they bought the whole lot.

"I don't think Fergus would cope with sharing me with another cat," Artemis laughed as they left the menagerie. "Although he did get along infamously well with Aunt Tina's Kneazle."

"How was staying with your Aunt and Uncle?" Rowan asked.

"It was brilliant. Uncle Newt and I found a nest of murtlaps," replied Artemis. Rowan was the only person at school who knew exactly how well-renowned a magizoologist her great-Uncle was. "It was a wrench to come home, to be honest."

"Artemis! Rowan!" a voice called out through the crowds. Looking down Diagon Alley towards the ice cream stall, Artemis made out a flash of vivid violet hair and a hand waving frantically above the heads of the crowd.

"Tonks!"

The two girls ran towards their friend.

"Wotcher, Artemis," said Tonks as Artemis neared her. Rowan arrived several second later. Artemis may have been small in stature, but she was a fast runner, especially considering how short her legs were. "Wotcher, Ro."

"How's your summer been, Tonks?"

"Not bad. Mum and Dad and I went to Belgium. I brought you back some chocolate, it puts Chocolate Frogs to shame," she said. "Although I've heard Honeydukes in Hogsmeade do some amazing sweets. I'm guessing both of you have been allowed to go?"

The girls discussed the upcoming Hogsmeade trips. They were so engrossed in their conversation that they didn't notice their friend Ben Copper approaching them, along with an entire family of red-headed wizards and two witches. Suddenly, Artemis felt a pair of hands cover her eyes from behind her.

"Guess who?" a voice said from somewhere above her head. She'd have known that voice anywhere.

"Bill!" she exclaimed, turning around and hugging her friend around the waist, who laughed and ruffled her already messy dark hair as he returned the hug.

Bill Weasley was two years above Artemis and her other friends at school, but the two of them had become close the year before after Bill helped Artemis and her friends to break into a Cursed Vault and save the school from a curse that was causing ice to spread over the castle.

Standing behind Bill was Ben Copper, a nervous boy with whom Artemis had been friends since her first term at Hogwarts, and Bill's brother Charlie, who Artemis hardly knew at all, despite their many mutual friends. She put her arms around Ben and pulled him into a hug, and exchanged brief nods of recognition with Charlie Weasley.

"How was your week with the Muggles, Charlie?" Tonks asked, as she began to hug the boys, much more exuberantly than Artemis had.

"Great," replied Charlie, smiling in a good-natured way. "I really loved the seminar."

"Cinema," Ben corrected him quietly.

"Hey, you lot, guess what," Bill said suddenly, and held out his hand. He opened his palm to reveal a shiny red and gold badge, emblazed with an ornate letter 'P'. "I'm the new Gryffindor prefect!"

"Wow!" said Rowan, who was staring wistfully at the prefect badge.

"Congratulations, Bill!" Artemis said, not mentioning the fact that Professor Dumbledore, the headmaster, had told her last year that Bill would soon be made a prefect.

"So you had all better stay out of trouble, or I'll put you in detention," he winked, and pointed a finger at Artemis. "I'm looking at you, Artemis Hexley."

"Ah, so this is the famous Artemis Hexley," said a short, slightly plump lady with red hair and a kind-looking face, who had to be Bill's mother. "I've been hearing a lot about you."

"All bad, I hope?" Tonks grinned.

"Not at all, dear," Mrs Weasley smiled at Artemis, and the corners of her brown eyes wrinkled slightly. "You've made quite the impression on my boys, you know."

"Mum!"

Bill and Charlie both rolled their eyes and shook their heads. Artemis felt her cheeks redden as Tonks started to cackle delightedly.

"Shall we go to Flourish and Blotts?" Bill asked, clearly wanting to change the subject.

The group made their way over to the book shop, with Bill and Rowan leading the way, discussing Bill's prefecture, the new subjects the third years would be taking, and the textbook list that had been included in their Hogwarts letters. Tonks was bringing up the rear, demonstrating to the numerous younger Weasleys - there were about four or five of them, all with flaming red hair - her Metamorphmagus abilities, whilst Mrs Weasley tried to hurry them all along. Artemis walked a few steps ahead of Charlie and Ben, and Bill's dad struck up a conversation with her as she did so.

"You're not Sara Hexley's daughter, are you?" he frowned. Artemis nodded in response. "She was always a powerful witch, that Sally. I worked with her back when she was in the Muggle Liason Office. Such a fascinating job. Has she ever told you about it?"

"Not really, no."

"That's a shame. You should ask her about it. You know, these Muggles are always coming up with some incredible ideas," Mr Weasley slowed down and fell behind in line with Ben and Charlie. "Now, Ben, you musttell me more about this syllabub that Charlie mentioned."

"Cinema," Artemis heard Ben utter once more as Mr Weasley began chatting animatedly to him, leaving Artemis by herself.

Bill's brother Charlie sped up to keep Artemis company, looking back over his shoulder at his father.

"Dad bloody loves Muggles," he whispered to her, shaking his head.

"You should have invited him along with you to visit Ben's parents."

"Don't say that too loudly, you'll give him ideas," said Charlie. "I don't know if Ben's parents could cope with all his questions."

Looking behind her, it didn't seem like Ben was really coping with all Mr Weasley's questions either. Charlie put his index finger to his lips, and then to his ear, so subtly that Artemis barely noticed him doing it. She frowned, and strained to hear the conversation that was taking place a few feet away.

"So," Mr Weasley was saying to Ben, "the bread goes in, and the toast comes out... Without magic, you say? Well, that... that's just stupendous."

Charlie raised his eyebrows fractionally, and Artemis both attempted and failed to disguise her laugh as a cough.

"He just takes it to the point where it's a bit weird, you know," Charlie muttered. "I mean, don't get me wrong, the sinner-whatsit was really cool, and you were right about them having great music..."

"They really do, don't they?" Artemis eyes lit up. She loved music, and Muggle music in particular. "What music did you listen to? Did you get to hear -"

"Charlie, dear, why don't you go and save your friend from your father?" Mrs Weasley interrupted Artemis with a loud sigh. Charlie shrugged at her and ran back to where Mr Weasley was still interrogating Ben on the subject of kitchen appliances. Mrs Weasley looked at Artemis, her gaze kindly, but scrutinising, all at once. "Did your mother not want to come and help you get your school things, Artemis?"

"Mum really doesn't cope well with crowds," Artemis said, trying to avoid the deeply pitying look in Mrs Weasley's eyes. She got the feeling that Bill's mum had noticed her own mother's absence before, probably having spotted her alone at Kings Cross Station.

Artemis was relieved when Tonks caught up with her, having untangled herself from Bill's younger siblings.

"Talking of not being here," said Tonks. "Where's Penny?"

"I don't know," Artemis replied. "She never replied to my letter."

"That's odd," Ben said, frowning. "It's not like Penny to miss out on a social arrangement."

This was true. Charming and cheerful Penny Haywood was a true social butterfly, the prettiest and most popular girl in their year. Normally, Penny was the one who would be organising get-togethers and dragging the more introverted Artemis and Rowan along to parties and gatherings. It was strange for them all to be here without her.

"She's still on holiday with her Muggle family, I think," said Artemis. "She sent me a postcard."

"Me too," Tonks chipped in, "but I've heard nothing else from her. Hey, hopefully we won't find her trapped in ice halfway through the term."

"I really hope not," Ben said, quietly. He had gone missing in the first term of their second year, and spent the best part of two weeks encased in the ice that had spread from the Cursed Vault, with no memory of how it had happened. "I'd quite like for us to just have a nice normal year at Hogwarts this year."

"With the famous Artemis Hexley around? Fat chance of that."

For Artemis, the final weeks of the summer holidays passed in a hot, sticky, dull haze. She entertained herself by practising Transfiguration and duelling spells in her attic bedroom (although Fergus quickly became tired of being turned into a cauldron), and venturing through Camden Lock, listening to music and trying out food from the market stalls, which she paid for with Muggle money "borrowed" from the drawer of her mother's bureau, and shared with Fergus.

After what seemed like an age, the morning of the first of September came around. Artemis was awake at the crack of dawn, and was already ready to leave an hour before she needed to. She waited in her room, watching the dial on her brother's old watch that she wore around her ankle, until it was almost time to leave.

"Mum!" Artemis called out, clattering down the stairs and knocking on her mother's bedroom door. "I'm ready to leave, I just need to pack my permission slip."

"Your what?"

"My permission slip for Hogsmeade weekends," Artemis strode into her mother's room. Her mother was at her dressing table, brushing her hair in the mirror. Artemis met the eyes of Sara Hexley's reflection and glared accusatively. "You didsign my permission slip, didn't you?"

"I'm sorry, I forgot," Mrs Hexley's eyes flicked away from the mirror, and she rose out of her seat and walked past her daughter without looking at her. "It's in my study. I'll sign it now."

Artemis watched her mother walk out of the room in disbelief. She caught sight of Fergus the cat watching the scene with his big green eyes. He miaowed sympathetically to Artemis.

"I'm not surprised either, Fergus," she sighed, crouching down to stroke his ears with her forefinger. "Want to place a bet on whether she will bother coming to the platform this year?"

Fergus miaowed again, and Artemis stood back up to follow her mother into her study downstairs. Sara Hexley was moving rolls of parchment and stacks of white Muggle paper over the desk, as if she were searching for something, albeit half-heartedly.

Artemis felt her jaw drop.

"Don't tell me you've lost it!" she said, glaring at her mother from behind her back. Mrs Hexley didn't turn around.

"You did put it on my desk like I told, didn't you?"

"Yes!" Artemis was outraged. "And you said you'd sign it as soon as you'd finished your work! I can't believe you lost it!"

"I'm sure it will turn up somewhere eventually." Her mother said breezily, straightening up and scanning the bookshelves.

"Eventually isn't good enough," growing angrier by the second, Artemis balled up her fists. "I'm leaving to go to school in ten minutes!"

"Well, why don't you go and fetch your luggage from upstairs? I'll keep looking and I'm sure I'll find it before you have to leave."

Artemis growled in exasperation and stormed out of the room, hearing the door slam satisfyingly loudly behind her. She dragged her luggage down the stairs, muttering angrily to herself, before collapsing on the bottom step next to the front door with her head in her hands. Fergus rubbed his ginger cheek against her arm, and she unfolded herself to scratch him under his ginger chin.

"At least I know I can always rely on you, Fergus," she whispered.

Her mother appeared in the doorway of her study, wringing her hands and looking at the floor.

"You can't find it, can you?" Artemis asked her. Sally Hexley shook her head, not meeting her daughter's eye. "Brilliant. The one thing I ask you to do for me this whole summer, and you can't even do that."

"I'm sure that your form teacher will be able to sort something out," her mother said, looking up and straight over the top of Artemis' head. Artemis was too incensed to tell her mother that there was no such thing as a 'form teacher' at Hogwarts. "But you need to go now or you'll miss the train. I'll walk you as far as the station."

"You know what? Don't bother," Artemis stood up and grabbed her school things, giving her mother one final scathing look before she opened the front door. "I'll go by myself. Come on, Fergus, we're leaving."

Artemis felt a lot better once she and Fergus were safely on the train with her friends. She sat in a carriage with Rowan, Tonks, and Penny, and told them all about the morning's drama.

"So, she lost the permission slip?" Tonks said. "Does that mean you won't be able to go to Hogsmeade?"

"I don't know," said Artemis, glumly.

"Don't worry, Artemis," Rowan reassured her. "If you talk to Professor Sprout, I'm sure she will send your mum a new one."

"That's a good idea, Ro," Artemis turned to Penny, who had been very quiet so far, considering how long it had been since they had all seen her. "How was your summer, Penny?"

"Oh, it was good, thank you," Penny sounded breezy, but Artemis noticed her blue eyes flicker slightly. "I was sad to miss going to Diagon Alley with all of you, though."

As the conversation continued, Artemis paid close attention to her friend, scrutinising her carefully. Despite Penny's summer in Cornwall, her usually fair skin looked paler than ever, and although she spoke brightly, there something that just wasn't the same about her. Rowan and Tonks, however, seemed not to notice anything.

Perhaps she was just imagining it, Artemis thought. But when they got to Hogsmeade station, she was sure that Penny flinched slightly when she saw the horseless carriages, and for the whole journey to the castle, poor Penny looked physically sick.

"Are you feeling alright, Penny?" Artemis whispered, as they climbed out of the carriage and walked into the entrance chamber of the castle.

"Oh, yes," said Penny, and she smiled and nodded at Artemis. Now that they had disembarked from the carriage, some of the colour had returned to her face, but she still looked restless. "A bit woozy, that's all. I don't think I ate enough at lunchtime. I wonder what food there'll be at the feast."

Once they were in the Great Hall, Artemis felt a familiar warmth spread over her. She felt more at home at Hogwarts than she did in her own house in London. The four girls took seats at the Hufflepuff table ready for the Sorting Ceremony and start-of-term feast. Before they could start eating, however, Professor Dumbledore stood to make his yearly start-of-term speech, welcoming the first years, and introducing the new Defence Against the Dark Arts professor.

"Really? That's the third one we've had in three years!" Tonks hissed across the table.

"They do say the job is cursed," said Penny.

"I wonder what happened to Professor Topsy."

"Didn't you hear?" Penny asked. Artemis noticed that she didn't seem quite as excited to share gossip as she normally did. "He's in St Mungo's. He got really badly burnt when the professors were freeing the Ravenclaw Quidditch team from the Cursed Ice last year."

"In hindsight, someone who drank as much as Professor Topsy probably shouldn't have been so close to all those Fire-Making Spells," muttered Rowan.

As it turned out, the rest of Dumbledore's speech was about the Cursed Ice itself.

"Now, I know many of you are worried after the issues we had with the ice last year," said the headmaster in a sombre tone. Artemis sat up a little straighter in her seat. "Having investigated the problem we have found that this ice was the result of an individual tampering in a Cursed Vault that was hidden in the school. The curse within the Vault has now been broken, and so we should not have any more difficulties with the Cursed Ice within.

"To those of you who have heard of multiple Vaults, and are concerned about these, I reassure you that the Cursed Vaults will only cause problems if they are tampered with," his face stern, he continued. "With this in mind, I must issue a warning to all students: do not go meddling with the Cursed Vaults. Any individuals found to be doing so will be punished most severely, particularly in the case of repeat offenders."

Dumbledore's eyes rested momentarily on Artemis, and she gulped, her face flushed. She looked at Rowan, Tonks, and Penny, and saw that their facial expressions displayed apprehension, amusement, and anguish, respectively.

"But enough about curses," Dumbledore smiled now, his eyes twinkling behind his gold half-moon glasses. "We are about to be blessed with some delicious nourishment. May the feast begin!"

The food appeared on the table, as if by magic. As they ate, Rowan turned to Artemis.

"Does this mean that you won't go looking for the Vaults again?"

"I... I don't know," Artemis frowned. "In the vision I had last year my brother told me to keep searching, but I don't want to be the one to release another curse on the school."

"So, what will you do?"

Artemis breathed deeply, and considered for a moment.

"I suppose that there's no harm in looking for clues," she reasoned. "I don't actually have to meddle with the Vaults, just find out about them."

"I thought you might say that," said Rowan, her doe-like brown eyes filled with concern as she looked at Artemis through the lenses of her silver-rimmed glasses. "Are you sure that's a good idea? You heard Dumbledore, you could get in a lot of trouble."

Artemis sighed.

"Well, I always seem to attract trouble whether I'm looking for it or not," she said. "But you're right. The Cursed Vaults aren't hurting anyone. And like Ben said back in the summer, it would be a nice change to just have a normal year at Hogwarts for once."