'Uhh…' Bagsy trailed off. 'Chancibibbly!' she cried out abruptly as the name hit her.

Mezrielda, with the dead serious expression of someone about to play in the final of the quidditch world cup, darted out of her seat and rushed to the C section of the library. Bagsy followed with a victorious grin. She was sure no one existed with such a name, let alone an author with their book in the school library.

'Ha!' Mezrielda laughed victoriously, grabbing a small grey book off of a shelf and waving it at Bagsy. 'That was barely even a minute,' she added, one hand on her hip. 'It took you a pitiful twenty-four to find Pnaruneblum.'

'That's because you cheated! How was I supposed to know it began with a silent P?'

'Because it was obvious,' Mezrielda retorted.

Often times Mezrielda got bored of her work and, in demands most people would find outright rude, would convince Bagsy to stop her own work to entertain her. Bagsy didn't mind.

Her first idea had been the one-word story game. In the game, they'd take it in turns to say one word before the other continued the sentence, until they'd be left with a very odd story indeed. Mezrielda had a habit of using the words goth, black, and preposterous a lot, as well as deliberately picking words she must realise Bagsy didn't know the meaning of. She'd denied this, of course, but when she had said sesquipedalian Bagsy had thrown her hands in the air.

'Are you kidding me!?' she'd said.

Mezrielda had shrugged nonchalantly. 'Oh, you don't know that word? I thought everyone did.'

'You absolutely did not think that.'

'It means a word with many syllables or refers to someone who has a habit of using long words. It's rather ironic, really, given I use words someone with even basic literacy has heard of,' Mezrielda had breezed as if she hadn't been using words like euouae (a cadence in medieval music) or incomprehensibilities the entire game. 'Oh, you don't know what incomprehensibilities means?' Mezrielda had asked, feigning an innocent expression. 'Would you say you can't… comprehend it?'

'Yes! I very much would!' Bagsy had seethed.

'That alone is evidence you can.'

'Can you choose a different word?' she'd groaned.

Mezrielda had grinned. 'Floccinaucinihilipilification.'

And that was how they'd found themselves playing a different game. Instead of real words, Bagsy had suggested they make up names and that if the other person managed to find a book in the library by that person they'd win. Despite names such as Hofflepoffle, Jimmyjohungus, and Bagsy's personal favourite, Dunce, they had yet to find a name that didn't have a corresponding book.

Mezrielda went to return the book by Chancibibbly when she paused. 'Huh,' Mezrielda murmured, reaching into the gap in the shelf. 'There's something back here,' she explained to Bagsy, who was looking at her quizzically.

'What?' Bagsy asked, walking closer and peering between the books into the darkness. She couldn't see anything with Mezrielda's arm in the way, though.

'Hold on,' Mezrielda muttered, pulling her arm back out and flicking her wand out form her sleeve with an unnecessary flourish. 'Accio,' she cast. Suddenly, a small rectangular pack of cards rushed out of the gap at Mezrielda. Without thinking Bagsy's hand shot out and caught it when it was inches from hitting Mezrielda square in the face. 'Ehem,' Mezrielda coughed awkwardly. 'Perhaps that charm needs some practise.'

'Perhaps,' Bagsy agreed, inspecting the pack of cards. 'Changelings,' she read out loud.

'What?' Mezrielda frowned, leaning in to look at the pack as well, their heads bowed close together over the item.

Bagsy continued to read. 'A fun, hidden role game for every witch, wizard, spellcaster and child.' She pursed her lips in thought. 'This sounds fun,' she said after a pause.

'It can't hurt to give it a once over,' Mezrielda agreed.

They spent a few minutes reading the rules and inspecting the cards as Bagsy's excitement grew. 'This sounds so cool!' she buzzed. 'Everyone is allocated a role at random and, depending on what they've been given, they either want to lie and pretend they aren't a changeling, or figure out who the changelings are!' Bagsy spread the cards out on the table. 'It says you need a minimum of five cards in play, but the cards have minds of their own so one person can play with four enchanted cards if they wanted. Wow… how on earth did they manage that? Enchanting cards to have personalities and speak and lie or deduce who's lying…' She shook her head in amazement. 'That's some impressive magic.'

'Bagsy,' Mezrielda said suddenly, her brow furrowed as she inspected a card. 'I think the magic has worn off.'

'What!?' Bagsy squealed sadly.

Mezrielda nodded solemnly, pointing at the cards. 'Unfortunately, whatever enchantment was keeping the cards working seems to have fizzled out. None of them will activate.' She picked one up and shook it back and forth to prove her point.

'So, we can't play…' Bagsy deflated, feeling crushed. She'd been so excited to give it a go.

A lack of excitement wasn't the worst of Bagsy's worries, though. Panic was all she felt the day before Christmas; she had no idea what to make for Mezrielda's gift. She had already collected a few different cool looking ornaments she'd spotted around the castle, but that was what she'd given to Mezrielda last year, and the year before. She had to think of something better this time around. Besides, she'd had such a fun time hanging out with Mezrielda over Christmas, so she wanted something a little more special to give her friend.

That was when it hit Bagsy as she sat, chewing on her quill in thought. Mezrielda wasn't just her friend. She was her best friend. With a pang, she wondered if she was Mezrielda's best friend, too? Did Mezrielda do best friends? It didn't feel like it. Maybe if Bagsy got her a really cool present, she would.

'Bagsy,' Mezrielda asked suddenly at dinner.

'Yeah?'

'It's Christmas Eve.'

'Yeah…?' Bagsy said again.

Mezrielda shifted in her seat. 'Only Maisy and I are in the Slytherin dorm right now,' she explained, her expression closed off.

Bagsy paused in thought, trying to piece together exactly what Mezrielda was trying to say. She often hated it when people didn't just state outright what they wanted yet, somehow, when Mezrielda did it Bagsy only felt endeared to her.

'Actually, never mind,' Mezrielda said abruptly, returning to her pecan pie. 'It's nothing.'

'Do you think the other Slytherin girls would mind if I used one of their beds while they aren't here?' Bagsy asked, catching on, and feeling a familiar hint of pride at how good she was getting at understanding Mezrielda.

Mezrielda shrugged, tossing her hair over her shoulder importantly. 'What they don't know can't hurt them.'

'What if Maisy tells them?'

'No one believes anything Maisy says, she lies so much. Who would believe that you, Bagsy Beetlehorn, Hogwarts biggest coward, who can barely spend ten seconds at the Slytherin table without cowering like a dog, and who faints at least once a year, would brave the Slytherin common room not just for an evening, but a whole night?' Mezrielda shook her head. 'Absolutely ludicrous.'

'You could've left it at coward,' Bagsy grumbled.

Mezrielda shot Bagsy a sideways glance. 'You're not really a coward, I'm under no delusion,' she informed her stiffly. 'I've seen what you can do when something has to be done.'

Bagsy held back a shudder, feeling as if she was trapped in a small, red, wet place with sharp teeth circling around her. She took a breath, pushing the thought from her mind. 'You know what?' Bagsy said. 'That sounds like a fun idea. A Christmas sleep over! Count me in.' Mezrielda nodded in approval, as if she was her teacher and Bagsy had finally given in a satisfactory piece of homework. 'Have you asked Maisy if she's okay with it?'

Mezrielda placed her wand to her throat and turned in the direction of where Maisy was eating alone. 'Reposurrus,' she murmured, before announcing, 'Bagsy is spending tonight in the dorm with us.' Maisy startled, glancing around in confusion for the owner of the voice that had somehow materialised in her ears before seeing Mezrielda from across the hall. She tilted her head, looked at Bagsy, then smiled and shot them a thumbs up. Bagsy smiled back happily, her excitement growing.

By the time Bagsy was shuffling her way to the Slytherin common room, Bill draped over her shoulder and Eldritch perched on her arm, she still hadn't figured out what else she could gift Mezrielda for Christmas.

The Slytherin common room was in the dungeons, and as Bagsy descended she pulled her dressing gown tightly around herself. It was old, handed down to her from Bontie, and had cartoon griffins printed over the white fluffy fabric. She reached a bare stretch of stone wall and knocked before politely waiting. After a while, the stone slid to the side and, for the first time in her life when she knocked on the Slytherin common room door, the person who answered was the person she was looking for. 'Mezrielda!' Bagsy smiled. Mezrielda held a finger to her lips and lent out into the corridor, looking both ways. 'What-?'

'Non-Slytherin's are strictly not allowed in the common room,' Mezrielda explained. 'It's only because Maisy is the only other Slytherin who's stayed behind that we can get away with this. I just have to make sure you haven't been followed.'

'Who would follow me?'

'I don't know. Shut up,' Mezrielda responded lamely, before grabbing Bagsy's arm and pulling her inside.

The Slytherin common room felt like a mysterious, underwater shipwreck. The windows overlooking Hogwarts lake let gentle turquoise light fill the space, and the ceiling was filled with gothic chandeliers that flickered with green fire. The sofas, unlike the plush, many-cushioned ones in the Hufflepuff common room, where low backed, button-tufted and dark green. They looked very posh and proper indeed. There was one armchair that looks far more impressive than the rest of the furniture, sitting smugly in prime position next to the fireplace.

Bagsy caught glimpses of decorative skulls, dark wood cupboards and ornate desks with impressive chairs stationed by them. Tapestries of formidable medieval looking spellcasters in the middle of battle, escape, or complex puzzle solving lined the walls. A massive portrait of a serpent hung over the mantel piece, where a fire was crackling away. It all felt very grand in comparison to the friendly, cosy Hufflepuff space and it smelt like how Bagsy imagined the top of a snowy mountain smelt – crisp, fresh, and isolated all at once. It felt just as cold, too, but a quick cast of teporiem from Mezrielda, and a hurry towards the fire place, solved that problem.

With a second glance around the Slytherin common room, Bagsy made two observations; firstly, there wasn't too much furniture, but still a fair amount that was evenly spread across the entire room. Secondly, the Slytherin common room was rather large, and rather long.

A smile broke out onto Bagsy's face. 'Have you ever played the floor is lava?' she asked. It had been a useful game for Bagsy growing up, given it only needed one player, and made use of large, empty spaces like her home.

Mezrielda titled her head quizzically.

A few minutes later Bagsy and Mezrielda were standing in precarious positions on sofas, or on the mantel piece holding onto the serpent portrait delicately so as not to accidentally rip it off the wall.

'I'm going to get to the other side first!' Bagsy teased Mezrielda. All that practise in Thaumathletics was paying off.

'Don't be ridiculous!' Mezrielda said, nearly tripping and pulling herself, and the serpent portrait, onto the floor. 'You beat me? Preposterous.'

The game had been made only more intense by a spell from Mezrielda that made the floor appear like the surface of a deep, black lake with creepy figures swimming just below the reach of the light. It freaked Bagsy out, but she wasn't going to let that stop her – she knew Mezrielda had deliberately made it scary to sabotage her, and she wasn't going to give her the satisfaction of being right, even if her knees were shaking uncontrollably.

'What are you two doing?' Maisy asked, walking into the common room from the girl's dorm with a steaming mug in her hand, peering curiously at them from behind her rose coloured glasses.

Mezrielda instantly hopped down from the mantel piece with as much elegance as she could muster, dusting herself off and brushing her hair neatly over her shoulders, before dismissing the enchantment on the floor. 'That's none of your business,' she said.

Maisy looked down at the now no longer enchanted floor, then back up at them. 'I can't believe this,' she breathed. 'Mezrielda Glint is playing a child's game. The world must be ending.'

Mezrielda bared her teeth. 'No one will believe you.'

Maisy shrugged, looking slightly upset.

'Do you want to join us?' Bagsy offered. Mezrielda's head snapped angrily in her direction as she breathed sharply out of her nose. 'What? She's letting me use the Slytherin dorm, it's the least we can do,' Bagsy argued.

Mezrielda crossed her arms and looked down her nose at Maisy. 'Fine,' she said at last. 'But it will have to be a different game. This one is far too childish for me.' Bagsy held back her need to point out that Mezrielda had been very much enjoying it before Maisy had arrived.

They settled on charades and Bagsy couldn't help but feel as if there was no point in her being one of the guessers, given Maisy and Mezrielda were so quick with their deductions. Bagsy barely finished imitating someone with a large belly before both of them called 'Blythurst!' out excitedly.

'I said it first,' Mezrielda scoffed.

'Actually,' Bagsy cut in awkwardly, twiddling her thumbs. 'I think Maisy was a hair faster.'

'Rematch!' Mezrielda declared. 'Pick another word, a better one this time!'

And so it continued, until it got to Mezrielda's turn and she'd pick something so obscure and longwinded that neither Maisy nor Bagsy could guess it. Mezrielda had transfigured the table in front of them to look like a half-horse half-man thing with elongated arms and one big eye on its head.

'A centaur?' Bagsy asked.

Maisy shook her head. 'It can't be that. Centaurs have two eyes not one, and normal length arms, not ones so long, and the human part is in place of the horse's head, not stitched onto the horse's back behind the horse's head.'

'I give up,' Mezrielda muttered after only a minute of trying. 'It's a Nuckelavee. I suppose neither of you pay attention in Defence Against the Dark Arts, unlike myself.'

'Oh yes,' Bagsy mocked. 'You're very diligent.'

'Yes. I am,' Mezrielda confirmed, not noticing that her transfigured table was creeping up behind her, slowly reaching its unnaturally long arms and gnarled, sharp fingers around her. At the last second Bagsy stood up and kicked it backwards. Mezrielda spun around and realised what she'd failed to realise was happening. Bagsy was satisfied with the embarrassed flush that found its way onto Mezrielda's face.

'Very perceptive, too,' Maisy chimed in.

That had Mezrielda fuming. 'You don't get to talk to me like that,' she snapped at her. Maisy startled, narrowed her eyes, looked meaningfully at Bagsy, looked back at Mezrielda, and then raised her eyebrows at her. 'No one talks to me like that,' Mezrielda quickly corrected herself with perhaps the first barely-perceivable stutter of her life.

'You can play children's games, and you can get flustered,' Maisy noted. 'Perhaps you're human after all.'

Mezrielda looked ready to throw jinxes.

'Why don't we head to bed?' Bagsy cut in, trying to keep the peace.

'Great idea.' Maisy smiled, getting up and walking towards the dorm.

'See what I have to put up with?' Mezrielda growled. 'All she does is make up fibs to try and embarrass or insult you!'

Bagsy looked from where Maisy had left to Mezrielda and back again. 'If you say so,' she said calmingly. It was almost comical how quickly Mezrielda's anger dissipated and turned to her usual cold but not entirely unfriendly expression.

'I do say so,' Mezrielda sniffed importantly.

'Whatever makes you feel better.' Bagsy patted her on the back as they made their way towards the dorm.

'What's that supposed to mean?'

'Nothing, nothing, don't fret, my dearest Mezrielda,' and with that, Bagsy stuck her leg out and tripped her over.

'Why, you-!' Mezrielda hissed as Bagsy laughed and rushed away from her. 'Get back here!' she called, a light tone perceptible in her mock outrage.

By the time they'd finished chasing each other around the common room and went to bed, Maisy was already fast asleep.

'See you in the morning,' Bagsy said happily as she crawled into the bed next to Mezrielda's. The Slytherin girls' dorm was much larger than the Hufflepuffs' and had a calm, shallow pool in the centre of the large rectangular space. As Bagsy dosed off in the foreign green four poster bed, she heard the lapping of the lake against the castle walls far above their heads and found it the perfect lullaby to drift off to.