Bagsy didn't sleep that night. She stayed up in her room practicing the counter jinx for the leg-lock spell, hoping she was making progress, and checking outside her door for any suits of armour that might be creeping towards her. By the time the sun was poking over the horizon she'd taken a break from learning spells and look-out duty to write a letter to her sister. She knew her sister hated her full name as much as Bagsy hated her own, so naturally she addressed the letter to Rebontil Beetlehorn instead of Bontie.

She wrote about Hogwarts, and how it was as cramped as Bontie had told her. Mostly, though, she complained about how difficult she was finding everything – from the maze that was Hogwarts castle, to the mean tricks other students had been playing on her. She also wrote how nervous she felt about the double Defence Against the Dark Arts class she had tomorrow. She briefly mentioned that it wasn't all bad – Greenda Particularis, the girl she'd sat next to during the sorting ceremony, had seemed nice, and Tod Alden had been helpful.

She didn't mention the dark corridor and moving suits of armour, or the endless staircase. Bagsy worried she was imagining things, and worried even more that Bontie would think she was imagining things, too. Bagsy's hands shook as she wrote, just thinking of the strange events that had occurred, and all the torment she'd been through. She was tempted to ask Bontie to come take her home.

Resisting the urge to call for a rescue, and concluding that Christmas couldn't come soon enough, Bagsy signed the letter and pulled on her cloak.

The morning chill outside the castle walls was intense and Bagsy huddled beneath her thick cloak as her breath misted in the air. Her hands were cold from poking out of her cloak to hold the map as she checked it but besides that the temperature wasn't all that bad once she'd acclimatised.

The Owlery stretched high above her head and swarmed with birds. The floor was covered in large piles of hay that were scattered with owl droppings and the remains of mice and voles. Bagsy waited for one of the birds to swoop down to her and began attaching her note. Her sister still lived at home even if she had a job at the ministry, their house was so big there was little point in moving out, so Bagsy hadn't needed to memorise a second address.

She paused as she attached her letter to the outstretched owl's leg, noticing a boy on his hands and knees in the corner of the owlery trying to pull bricks from the wall. 'Um, hello?' Bagsy called out to him.

Tod Alden stood abruptly to his feet, letting go of the bricks he'd been trying to pry out, and looking like a dog who'd been spotted digging holes in the garden. 'Oh, goodness me, hello there.'

'What're you doing?' Bagsy asked. The owl on her arm was growing impatient and gave her hand a nip – luckily, not on the same finger she'd cut yesterday. Bagsy finished tying the note and the owl flapped off.

'I was going to ask you the same,' Tod responded, dusting his trousers importantly, 'but I deduce it has something to do with correspondence via parchment?'

Bagsy held back a giggle. Tod talked in an even worse way than Mezrielda. Perhaps the two were friends. Maybe Bagsy would ask Mezrielda if that was the case the next time she saw her.

'I couldn't sleep, so I wrote a letter instead. That's why I'm here so early.' Bagsy tilted her head and narrowed her eyes. 'It is very early, and I may be dumb, but there's no way you were sending a letter. Are you looking for something?'

'No, no, absolutely not.' Tod laughed as if Bagsy was being ridiculous. There was a moment of silence and Bagsy felt a shift in the air that she couldn't describe besides the fact it was cold. 'No, I was checking to see if the construction of the Owlery was up to scratch.'

Bagsy was about to open her mouth and protest that was the stupidest excuse she'd ever heard when, all of a sudden, she decided it made perfect sense. 'Oh. Of course. That makes perfect sense,' she said, no hint of sarcasm in her voice. Her whole body felt suddenly rigid, as if a small pulse of electricity was flowing through it, or her brain was a sieve, and a few very specific things were falling through its holes.

'Yes, it does. Shall we walk back to school? I believe we have Astronomy together on Wednesday mornings,' Tod said as he walked past Bagsy and out of the Owlery. Like an obedient solider Bagsy followed, feeling as though she were walking through thick syrup. 'I must admit, I'm far more partial to Astronomy classes during the day. We have it again at midnight, didn't you know?'

'No, I didn't,' Bagsy responded blandly. 'I was confused by my timetable. I was going to ask a teacher about it.'

'Well, I'm glad to have…' Tod paused and looked Bagsy in the eyes in an odd way, 'cleared that confusion for you.' Bagsy experienced a sudden stop – like she'd been flying a broom that had braked too quickly – and the strange tiredness she'd been feeling left. She blinked a few times, as if she'd just awoken.

'Oh, hi Tod,' she murmured, then glanced behind her in mild confusion as her mind caught up. She'd walked here from the Owlery, where Tod had been acting very normally, and not aroused her suspicion at all. 'Astronomy?' She asked pleasantly.

Tod nodded. 'Astronomy.'

Astronomy was taught by Professor Jones who, to Bagsy's great surprise, was the school nurse's twin. At least, he was in appearance. He shared the small stature of the nurse, who Bagsy had been informed was called Nurse Jones, but lacked any of the jittering, mumbling energy. Professor Jones was calm and moved with precise elegance, and he refused to repeat himself.

Bagsy found the first lesson of Astronomy easy enough. Anything that didn't involve direct spellcasting she could deal with, and she was feeling fairly normal when she walked out of the lesson. Mezrielda might have been in the same class but Bagsy had paid her little attention. She and Tod had spent most of the lesson discussing the different possible symbolisms of the constellation Auriga, the charioteer, and its significance in magical history. Tod had been far better at discussing this, of course, but Bagsy was happy enough to listen and contribute when she could.

After Astronomy was Defence Against the Dark Arts, the subject Bagsy had been looking forward to the least. Her sister's ominous words had stayed with her, and her stomach was working itself into knots. Tod didn't help either – he kept talking about all the different spells he knew that could stave off beasts of different kinds, and how confident he was feeling.

'I bet I can impress Professor Fitzsimmons with a perfectly cast protego charm,' he theorized.

'Professor Fitzsimmons is the Defence Against the Dark Arts teacher?' Bagsy checked, to a nod from Tod. She wasn't sure if that made her feel better or worse but either way Bagsy's spirits were so low that by the time they'd climbed the many stairs that led to the classroom she decided it was better to miss the lesson all together. 'I'm not feeling so good… I'm going to the bathroom.' She spun on her heels and hurried down the stairs, desperately pushing past the Hufflepuffs and Slytherins in her way. Tod didn't seem to mind and let her leave, turning to speak to one of his fellow Slytherins instead.

Bagsy was past the last student, her legs picking up speed, when the moving staircase gave a jolt and her robe caught on her foot, and she let out a yelp as she began to tip forward. A hand grabbed the back of her robes, there was a second yelp, and then Bagsy and her attempted saviour were lying in a heap at the base of the stairs.

'How clumsy can one person be!' Mezrielda growled from above Bagsy as she got off of her.

Bagsy let out a few panicked breaths and sat up. 'Sorry!' The other students were looking down at the pair, some with contempt, some with pity, and some with barely suppressed amusement. Bagsy looked up to see Mezrielda, already on her feet, was holding her hand out. Bagsy looked at it lamely.

'Come on,' Mezrielda snapped, opening her palm wide. Bagsy grabbed her hand, expecting to be zapped or thrown back down, but Mezrielda helped her to her feet and let go. No tricks, no pranks. Bagsy looked at Mezrielda suspiciously.

'Fine. I won't help you next time,' Mezrielda huffed, flicking her long black hair and walking up the stairs to the now open doors of the classroom.

Bagsy looked down the stairs, in the direction of the toilet, then gathered herself and walked up to the classroom instead. She was the last to set foot through the doors and when she did they thudded closed behind her on their own. Almost instantly she regretted her decision.

In the room there were desks and chairs, enough for each student, and a few empty cages hung from the ceiling, joined by skeletons of unknown creatures whose empty eye sockets seemed to suck Bagsy's soul away from her. Besides the other students there was no one in sight.

'Where's the Professor?' Tod asked, having walked to the far end of the classroom confidently, hands in his pockets as he examined a cluster of small skeletons with bony wings and sharp beaks. 'Are we supposed to teach ourselves?'

Bagsy looked up at a chandelier that hung from dark wooden beams criss-crossing the ceiling where a moth was flittering around the candles that dimly lit the room. She couldn't explain why, but her eyes knew it was their professor.

The moth descended, suddenly growing in size, its wings stretching out from one end of the classroom to the other. Bagsy wondered if she'd been horribly mistaken and it wasn't their professor after all - perhaps their first lesson was a test to see who could survive this horrifying beast.

When the giant moth impacted with the cowering students who let out cries of shock, there was an explosion of dust. Coughing followed the dust cloud and, as it disappeared, standing regally at the front of the room on a podium that hadn't been there before was their professor.

Professor Fitzsimmons stood to their full height, enlarged eyes moving slowly from one pupil to the next. With a click of their fingers, the dust vanished, and the classroom was perfectly clean.

'The head mistress teaches Defence Against the Dark Arts?' the Hufflepuff boy with a mohawk whispered scandalously to his friend.

'Yes. The head professor teaches Defence Against the Dark Arts,' Fitzsimmons corrected him. 'Itsuki Elmore, isn't it?' The boy with the mohawk nodded and gulped. He was a short boy and if it hadn't been for his ridiculous hair poking above the other students' heads Bagsy wouldn't have been able to see where he was. 'Well, Mr Elmore, I'm sure you are aware speaking out of turn is counter to learning?' Itsuki nodded. 'Good.' Fitzsimmons motioned to the desks. 'Be seated. Quickly, please.' Students rushed to grab the desks at the back of the class but Tod and Mezrielda didn't seem to mind, and both grabbed seats at the front, a few desks away from each other. Twice Bagsy tried to slide into a desk near the back only to be forced out by another pupil. She was certain Fitzsimmons could see the forceful pushes and spats for seats, yet they made no effort to stop them.

Eventually, the only desk was right at the front, and right in the middle.

Bagsy's legs seemed to grow progressively smaller and weaker as she walked closer to it. When she sat down, she didn't know if she was relieved or terrified. She looked to her left. Tod, a desk away, gave her an encouraging salute. Immediately to her right Mezrielda shot her a glare.

Fitzsimmons didn't need to speak loudly to command the classes' attention. 'As you might have heard, the first Defence Against the Dark Arts lesson any pupil takes is a test.' Murmurs erupted throughout the class. Fitzsimmons didn't ask for silence, but their eyes flashed dangerously, amplified by their large, bug like glasses. It didn't take long for the students to shut up.

Professor Fitzsimmons drew in a slow breath and spoke softly. 'This test is not one you can prepare for, nor is it one to worry over. You will not be harmed, I assure you, and its results are for my eyes only.' Fitzsimmons paused. 'I need all of you to close your eyes and sit as still as you can. You may find this test alarming – but remember, dreams often are.' Bagsy looked around her. Students were closing their eyes and sitting up straight and tense. 'You too, Bagsyllia,' Fitzsimmons added. Someone behind her laughed.

Bagsy faced forwards, took a breath, and closed her eyes. As soon as she had, the Defence Against the Dark Arts classroom vanished, and she found herself falling in darkness. Then, she found herself screaming.

Sunlight appeared in the pitch black around her, revealing the lethally pointed rocks she was falling towards. A second ago, she'd been in a classroom but now, by simply closing her eyes, she found herself falling in the middle of nowhere. Bagsy, looking around in desperation, saw a cliff face and vines whipping past her. Her mind grabbed onto a thought right at the back, tucked behind 'how to breathe' and 'forgetting what I'm looking for when walking into a room'.

The thought pulled itself forward and Bagsy felt it become real in her hands, as if this were a dream at her command. There was a weight in her palm; a portal grappling hook. When she was younger, she'd designed the fantastical concept and scribbled it into a blueprint, and even attempted to create a make-shift grappling hook that summer, but she'd never made anything like this. The grappling hook sparkled a deep purple in her hands, and she could tell from the gold, glowing rope that it really could summon portals.

As if it were entirely normal for a childhood drawing to appear in her hand, Bagsy aimed the portal-grappling hook at the top of one of the cliffs. The end shot off and disappeared into a dark portal and a second dark portal appeared at the top of the cliff where rope fastened itself. With a sudden jerk the machine pulled Bagsy, who barely hung on, through the first portal.

She was deposited out of the second portal, feeling as though she'd been shot through the icy liquid of a waterfall, and tumbled on to the floor as the portal-grappling hook vanished from her hands as quickly as it had appeared, like a sketch being rubbed out. How one of her silly drawings she'd made as a child had manifested itself was beyond her. Maybe she was dreaming. Maybe that's what Fitzsimmons had been hinting at.

Bagsy didn't have long to think on it as a rumbling from deep below roared around her. She glanced over the side of the cliff she'd landed on, seeing cracks forming along its side; the whole thing was collapsing. Bagsy scrambled to her feet and started running away from the edge, where the ground stretched out away from the cliff's edge towards a swath of trees. She wondered if she could climb one.

She reached the first tree and barely managed to scramble up, hands and feet aided by panicked adrenaline, her frantic mind not realising that climbing a tree wouldn't keep her safe from a giant sinkhole.

Looking around she saw the cracks travel from the cliff edge and near the trees; a web of dark lines slowly tearing the earth apart. The trees to either side of her were beginning to shake, some of them tipping over and crashing into others as crevices formed beneath them.

Bagsy looked at the trunk of the tree she was in and placed her hand to it. Her eyes caught movement and there, hidden amongst the leaves, she saw an odd creature. It was like a small stick man, but green, and with leaves for hands and a head. A magical creature like that would never live in a mundane tree, she realised.

Heart thundering, she gripped the branch above her. Bagsy wasn't sure what she intended to do, but she had to try something or face falling into the cracks. She pulled, and pulled, and pulled until the branch snapped off. It was as long as she was, just some plain old wood in her hands.

'What am I doing?' she asked out loud to herself, looking back up at the strange leaf creature, who shrugged back. The cracks were multiplying by the second and large sections of ground were falling into an abyss below, as if the world was an imploding egg. Bagsy didn't have long. 'What have I got to lose?' she breathed to herself, pulling her wand out of her robes. She pointed it at the branch and closed her eyes.

Nothing happened.

The ground beneath her split into a yawning crevasse and the tree and Bagsy fell down into it. She let out a wail as she plummeted, wand in one hand, branch in the other. In that moment her focus razored in on the branch in her hand. She had one more chance.

Eyes open she pointed her wand at the branch. She was unsurprised to find the wand wasn't her hornbeam wand but the walnut wand with a pewter core she'd received from Ollivander. Everything clicked perfectly, and though there was no brilliant flash of light, or exquisite mystical spark, Bagsy knew it had worked. She knew because the branch in her hand began to slow.

Hauling herself on to it, and gripping tightly, Bagsy watched the branch beneath her soar upwards and away from the darkness; a make-shift broom. It was horribly uncomfortable, and she dared not think about splinters, but she was no longer falling, and that was enough. She shot back out of the crevasse and into the air.

'WOOOO!' Bagsy called out in glee as the make-shift broom soared and broke through the clouds above. 'I DID IT!' she cried. 'I DID IT!'

She didn't celebrate for long, though, as the broom stuttered beneath her, and began to slowly descend. Bagsy held on tightly, suddenly aware of how high up she was. As she fell back through the clouds she saw, ahead of her, a collection of pine trees not being torn up by splintering ground. After guiding the broom carefully between the thick trees, she set down in the middle of a forest. She stepped off the branch, holding it to her chest for comfort, not believing what she'd just done, and wondering if the ground was about to fall away from her again. As strange as the events were, she couldn't deny the small warmth of pride in her chest at managing to achieve something.

She briefly remembered that this was a test and wondered if what was happening was all some strange illusion by Professor Fitzsimmons. Bagsy was probably sitting in the Defence Against the Dark Arts classroom right now, having a most unpleasant dream.

As this occurred to her, an agonized groan shook through the trees like a fierce wind, and Bagsy barely stayed on her feet, her robes and hair blasting out behind her. The trees around her seemed to sway and morph as if she were looking at them through a curved lens.

This noise was more terrifying than anything else Bagsy had experience in this strange place. It sounded unwelcome, as if it wasn't supposed to be there, and she had a sudden sinking feeling something had gone terribly wrong. Not willing to stick around and find out what was making that noise, she turned and began running, her mind shuffling through ideas as she moved. If she could make a broom from a branch, perhaps she could deal with whatever was approaching.

A root caught on her foot and Bagsy tumbled to the floor. She fell head over heels and rolled down a slope onto something bouncy, and the branch fell out of her hands but her grip on her wand was vice tight.

Whatever it was roared again.

Bagsy tried to sit up only to realise she couldn't. She'd landed in a web of vines and wood and leaves that had gripped her limbs, growing and tangling around them. She looked behind her to see the web reaching down into a dark pit, the branch a few feet below her, vines coiling around it.

The roar was louder now – whatever it was, it was drawing near.

Bagsy struggled harder, but the web wouldn't budge. She looked down at the make-shift broom, trying to figure out if she could reach it somehow. Then she noticed that the wood, vines and leaves around the broom were growing at an incredibly fast rate, reaching out and thickening. The make-shift broom glowed with magic, and its magic pulsed through the web, feeding it. At the sight, a plan formed in her mind.

Bagsy looked up and saw the creature responsible for the noise – and wished she hadn't. It had at least ten arms, each a different length, and with a different number of fingers, and skin that was so bright and so white it looked more like a tear in the world than a creature, but it's eyes…

Its eyes were wide and unblinking, and red like blood. They were dripping, too, as if made of sludge.

The creature lunged at her, a mouth Bagsy hadn't realised it had opening wide, ready to swallow her whole with awful rows of sharp teeth. She felt a kick of emotion, the one that usually demanded she cry, but instead she clenched her jaw, accepting her terror, but refusing to freeze.

Bagsy let go of her wand.

It clattered on to one of the vines and an explosion of vegetation, growing out of her magically pulsing wand, pushed the horrifying monster back. The white creature scrambled angrily at the wood and vines, its thinner arms trying to reach between them and grab her while the larger tried to break through.

Bagsy lay at the centre, cocooned in the warm web of growing plants, feeling exhausted. How she'd survived all these things in quick succession she had no clue, but luck was her best guess. Then the web disappeared, and she was falling into the dark pit below, her wand, and the broom, out of reach.