The DADA classroom looked like a set from a Gothic horror movie. Thick black curtains were drawn across the room's tall windows to block out natural daylight. The room was illuminated by the candles in the cast iron chandeliers and the flaming torches set in sconces along the stone walls. Gruesome pictures hung around the room. Most depicting witches and wizards being attacked by magical creatures or showing the aftermath of dark curses. Buffy slowly lowered herself into her chair, her eyes glued on the nearest painting of a Dark Wizard standing in a graveyard, the accoutrements of a Summoning ritual at his feet whilst all around him Inferi climbed from their graves to do his bidding.

She pulled her eyes away from the picture to examine the rest of the classroom. Chains and manacles hung from the wall to one side, a large wardrobe with two sets of doors and a mirrored panel stood in the far corner. Despite it being a mahogany wardrobe, it somehow managed to exude malicious intent. Buffy eyed it speculatively, wondering if it harboured some kind of dark creature. She knew that her boggart would have drooled over that wardrobe.

Buffy was surprised to see an elderly witch with short-cropped grey hair wearing Edwardian style clothing sitting at the DADA teacher's desk. The woman had been sitting so quietly that Buffy almost didn't notice her. When she caught Buffy's gaze she gave the Slayer a tiny nod of acknowledgement, before Roz Moody distracted Buffy.

"I can't find my quillbox," the sandy-haired girl muttered, digging into her bag. "Ah, there it is! It's worked its way right to the bottom."

When Buffy looked back over to the teacher's desk, the elderly witch was once more watching the students as they entered the room. Buffy tilted her head, assessing the witch. She didn't look dangerous, but Buffy knew that looks could be deceptive. Little old ladies could be dark demons too.

"Is Professor Merrythought a good teacher?" Buffy asked Roz quietly.

Roz stopped fiddling with her quills. "She's the best," Roz replied. She shot a wary look to the front of class, her gaze skipping the elderly witch and focussing on the area in front of the blackboard. "When she comes in, don't let her appearance fool you. She's fast with the jinxes and I've never known anyone to get through her shield charm. She was an Auror in her youth and they say she was one of the best. Back then, there were a lot more Dark Wizards than there are now. Not that Grindelwald isn't big trouble-. Oops, she's here. I've no idea how she appears from nowhere like that."

Professor Merrythought had risen and walked out to stand in front of her class.

"Welcome to a new academic year," the DADA teacher began, pacing up and down in front of the blackboard as she addressed her students, "I know that I won't be the only teacher warning you that the OWL year is hard..."

Buffy slumped in her chair. If the other students were going to find this year hard, then it would be nearly impossible for her.

"...and you also know I won't tolerate laziness in any of my students. This year, the only excuse you have for not handing in your homework on time is being dead! Did you hear that Miss Parkinson and Miss Moody?"

Roz shifted on her seat and shot Buffy an embarrassed look.

Merrythought continued sternly, "Those who wish to fool around are wasting my time, the time of their fellow students and will be sent from my class. I shall no longer teach them. I am sure they will have great fun explaining to the Headmaster and their parents why they have been dismissed from a core subject in their OWL year."

Buffy was sure she heard several students gasping.

"These days," the teacher went on, moderating her tone and direction of her pacing, "defending yourself against the Dark Arts is more important than ever. Grindelwald's influence has stretched throughout Europe and the Americas and, although he remains absent from British shores, you should not become complacent," her eyes flicked over to Buffy as she came level with her, "because you never know where his gaze will land next."

Merrythought's long skirts swished as she continued past, both Roz and Buffy turned in their seats to watch her.

"Some of you..." Her eyes went to Penelope Parkinson and the girl sitting next to her, then darted to a group of Hufflepuff boys at the back of the class. "...would do well to practice your defences at the Hogwarts Duelling Club. We hold meetings twice monthly. There is no excuse not to attend, it's not as if you've anything better to do on a Saturday night."

Several students groaned loudly, reminded of the mountain of homework and extra reading that had already invaded their weekends. Professor Merrythought grinned and Buffy saw a glimpse of the mischievous girl Galatea had once been.

Roz Moody nudged Buffy. "Fancy going?"

"I don't know anything about wand duelling," Buffy replied. Remembering magical incantations and wand movements seemed a lot harder work than stabbing someone with a sharp weapon.

"Alastor says duelling is a more stylised form of fighting, but he says it's great practise for having jinxes and hexes thrown at you and then casting them in return. We could always go along and watch a few bouts before signing up."

Buffy hesitated. What if she lost control of her Slayer side while duelling? Would she be able to restrain herself? She didn't want to lose it and impale an innocent kid on her wand.

"Can we go, just once to see?" Roz wheedled. She pulled a face. "None of the Hufflepuffs want to go and I don't want to go by myself."

Buffy found herself agreeing. "Only to watch." She'd get the gist of what it felt like and if she thought it too dangerous (for other people) she'd leave.

Galatea Merrythought continued underlining the benefits of Duelling Club, talking about fighting styles and famous duellers of the past. Every so often she'd throw a question at Abraxus Malfoy or Marcus Lestrange; from their enthusiastic replies, it seemed they were long-standing members.

Then Professor Merrythought's eyes moved from Malfoy to the boy sat beside him. "What about you, Riddle? Can we persuade you to join our little group of duellists this year?"

"I don't wish to disappoint you, Professor Merrythought," he replied, cheeks tinged pink at being singled out, "but I don't think duelling is for me. I'm happier being a scholar than a fighter."

Remembering how Tom had laid into the gang outside Stockwell Town Hall, Buffy let out a low huff of disbelief. There was no way he could have heard her, they were sat a couple of desks apart, yet he looked over. Dark eyes locked on hers, a simmering brew of anger, disapproval, and pain in them.

"Come, come, Riddle," Professor Merrythought protested, "don't be so stubborn. What if you marry and start a family? If a Dark wizard came to your door, you'd soon change your mind and wish you'd practised duelling then."

"I don't think that will ever happen," replied Tom with a show of shy hesitancy. "Who'd would want to marry a boy like me?"

The room erupted with objections. Buffy clearly heard Penelope Parkinson cry, "I'd love to marry you, Tom!"

Buffy made a retching noise and slumped forward onto her desk, burying her face in her arms and groaning. "Ugh! Kill me now."

Roz Moody giggled. "I think he overdid it as well. Riddle's a bit of an actor."

Riddle and Malfoy scowled at Roz. Since the teacher wasn't looking, she stuck out her tongue at them. She giggled again when they looked affronted. "Or maybe you like the tall, dark, and brooding type?"

Buffy didn't look up. "Nope," she mumbled into the crook of her arm. "That Pawing Parkinson is totally cringe-worthy. She's totally an insult to girl-power."

Roz looked over her shoulder so fast that her braid bounced. She turned back, leaned into Buffy and whispered, "She's sending Riddle love-lorn looks now."

"Is he sending any back?" asked Buffy, a little quicker than she'd intended.

Roz checked Tom's side of the room. "No. He's staring straight ahead now."

"Maybe he's got better taste than I thought," Buffy muttered.

"I've never seen him with a girl," mused Roz, "just boys."

Buffy's head shot up. "Really?"

Roz's eyes widened. "No, not like that. I mean... he doesn't date. Not boys or girls. He mainly hides out in the library."

Their whispering drew the professor's attention. "You," she pointed at Buffy who was still slumped over the desk. "Yes, you with the hair and the weak spinal problem."

Behind her, a student laughed like a dying donkey and another tittered. Aware of eyes burning into her from all directions, Buffy sat up sheepishly and gave her hair a self-conscious pat.

"What's wrong with my hair?" she asked Roz. She'd styled it that morning into a messy bun to keep it from falling into any strange concoctions in their Potions class.

From the corner of her mouth, Roz whispered, "It's fine."

"Ha!" said Merrythought. "The threat of having bad hair got your attention! Are you gels coming to the duelling club or not?"

"Yes, Miss," Roz answered before Buffy could say anything. "Buffy was as keen as me to join."

That was going too far. Buffy aimed a kick at Roz's leg under the table.

Roz winced but ploughed on relentlessly. "My brother says everyone should learn the basics and it's good to have hexes thrown at us on a regular basis. He says it sharpens the reflexes and we can never be too prepared or become complacent."

"That's true," Buffy admitted. She had memories of Giles saying something similar to her when she'd whined about going to the Mall instead of training. She couldn't resist adding. "Also, it's good that we know how to defend ourselves in case our future husbands aren't around to protect us." She fluttered her eyelashes, fake simpered, and added, "Because we're totally date-worthy and the marrying kind."

A small crease appeared between Merrythought's eyebrows, but she rallied. "Excellent!" she said. Taking out an ebony wand, she began addressing the class once more. "I hope more of you gels take note and join us. Now, for the subject of today's lesson we shall-."

A piercing shriek ripped through the quiet classroom and a dark shape swooped down from above. Uproar ensued. Students screamed. Others, Buffy included, sprang from their seat, drew their wands and took a defensive stance in the aisles. Several desks behind Buffy's, Penelope Parkinson fell sideways to lie across her friend's lap.

Penelope squeezed her eyes tightly shut and clutched at her chest, whimpering, " My heart stopped. I'm going to die..."

Buffy didn't think the girl was anywhere close to dying. She'd seen her crack an eyelid and peek over at Tom Riddle. Tom didn't appear to have noticed. He sat facing the front of class, his arms folded, and looking bored. Next to him, Malfoy watched the dark creature swooping about the room with a gleeful expression.

Penelope Parkinson let out another loud, and pathetic, moan. Her friend began wafting a sheet of parchment in the prostrate girl's face. Satisfied there was no real threat, Buffy returned to her seat. At the same time, Roz climbed out from beneath the desk where she'd been hiding. For a little while longer, the DADA students watched the cloaked Dementor shape hover and swoop in the air above them.

"Well, that was an interesting display," drawled Merrythought sarcastically. "Very few of you showed a fast reaction to danger." Her eyes rested on Buffy, then moving on to Marcus Lestrange and Victor Avery who'd also jumped out, wand in hand, to face the creature. Merrythought went on, "Class, let me introduce you to my fake Dementor. Since we have a Dementor at large in the area..."

Buffy's focus was now fully on the grey-haired Professor.

"... and yes, the Ministry are taking it seriously, we will be going over Dementors once again. So what do we know about these Dark entities?"

No one raised a hand.

Finally, Tom put up his hand and, at Merrythought's nod, said, "Classified by the Ministry as being amortal and a non-being, they are used as guards at the Wizarding prison, Azkaban." Smiling pleasantly, Tom added, "They secure a victim and feed off them by forcing them to relive their worst memories over and over again. They can also suck out souls. This is called a Dementor's Kiss."

"Excellent, as usual Riddle. Five points to Slytherin!" exclaimed Merrythought. "Where is the location of Azkaban?"

Penelope Parkinson raised her hand and called out, "It's a secret, Miss!"

"And what about the Dementor's appearance? Miss Moody?"

Roz had been searching in her bag, trying to find a missing textbook. "Oh!" She looked up at the floating fake Dementor. "Er, ten feet high... Um, grey skin, they don't have eyes and they wear a long, dark cloak.|"

"And what would you do, if you found yourself face to face with one..." Merrythought pointed around the room and her finger landed on Buffy. "Miss Summers?"

Buffy stared blankly at the professor. "If I met one? She curled her lip at the ragged cloaked, fake Dementor hovering above her. "I'd probably say that it must be blind to have picked out that outfit to wear. Then I'd fight it."

"How? How would you fight such a creature?" Merrythought pressed. "What is it these dark entities fear the most? The answer is not sarcasm or quips!"

'ME' whispered her inner Slayer. 'They fear me.'

Buffy knew she had to come up with the correct answer. They were staring at her, Merrythought and the rest of the class and she felt under pressure. "Er, is it a Riddikulus spell?"

"Boggarts!" snapped Merrythought. "Riddikulus is for boggarts! Miss Summers, write me a foot long essay on the difference between Boggarts and Dementors, to be handed in at the start of the next lesson."

"Did she just give me extra homework?" Buffy whispered to Roz. At the other girl's nod, she groaned, "Everyone, including Parkinson, has a brain except me. I'm so gonna flunk everything."

"You'll be fine," Roz whispered back, warily watching Merrythought in case she found herself with extra homework as well. "It was just a mistake."

"Who can anyone tell me the correct answer to that question?" the Dada teacher barked, her eyes scanning the room. Buffy was pleased to see only one person's hand went up until she realised whose hand it was.

"Dementors fly in face of a Patronus," replied Tom smugly. "The incantation to summon one is 'Expecto Patronum'."

Buffy muttered, "Freaking Geek."

Roz sniggered. "I bet he can't summon one."

"Well done, Tom. At least, someone has their wits about them. Lestrange!" Merrythought's focus went to Marcus, who'd been whispering to Victor Avery. "Tell me more about what the Patronus does."

Marcus's eyes glittered with mischief. "It's a spell to drive off Dementors, Professor."

Galatea Merrythought rolled her eyes. "Very droll, Lestrange. I shall expect an extra foot on your homework essay." She walked briskly over to the blackboard and, with a quick wave of her wand, writing appeared. "Since most of you have forgotten everything except your names over the summer, I shall go over the Patronus Charm and its usage.

'A spell to use as a weapon against the Dark Side!' The Slayer side of her tingled with awareness. Her breathing slowed and she was aware of every word as the teacher spoke.

The DADA teacher went on, "No one knows who invented the Charm, although its use in Wizarding history is well documented throughout history. One of the earliest recorded accounts is of a young wizard called Illyius. He cast a Patronum Charm to create a corporeal mouse. Despite its diminutive size, that tiny creature drove off an entire army of Dementors led by the Dark Wizard Raczidian.

"Does anyone know what happens to Dark wizards who try to call up a Patronus?" Everyone remained silent, looking at her expectantly. "They fail. Only the worthy, the pure of heart, can cast a Patronus be it incorporeal or corporeal..."

Across the class, Buffy heard Tom give a low, mocking snort.

Merrythought continued, "When Raczidian tried summoning his inner guardian, his Patronus, the spell backfired on him. From out of his wand poured a legion of maggots which turned and slowly devoured his body."

"Ugh," squeaked Penelope Parkinson. "I feel sick."

A memory nudged and Buffy, without thinking, whispered, "Raczidian's other name was Norman Pfister."

"Who?" Roz asked, puzzled.

"The bug guy. He was a salesman, part of the Order of Taraka, he..." her voice trailed away. The memory she'd seen evaporating like mist when the sun's rays hit it. Buffy blinked. Aware of Roz's bewildered expression, and not wanting to lose her friendship, Buffy shrugged it off. "Um, never mind, I have strange memories. Not all of the good."

"Miss Summers!"

Buffy jumped guiltily. "Yes, professor?"

"Stand up, gel."

Buffy rose to her feet, blushing. Behind her, several of her classmates sniggered.

"Two people are talking in my class," Merrythought said. "One of them is paid to do so, the other is not. Since you have so much to say, you can come to the front of the class and watch while I summon my Patronus," she smiled craftily, "and then I shall expect you to do the same.

Shamefaced, Buffy left her seat. Without meeting anyone eyes, she went to stand with the professor.

"A Patronus Charm," said the professor, "is a difficult piece of magic and very few witches or wizards are able to summon one. Some believe they are easier to summon once you've experienced some kind of psychic shock. That is because the Patronus is personal to you and often lies dormant until needed. Now watch me."

The elderly witch began to make circles with her wand, slowly concentrating her power. "As you do this, you need to concentrate on your happiest memory. Take a single happy thought and focus on the emotion it causes inside you. Once the power has gathered, use the incantation 'Expecto Patronum!"

A wisp of silvery light formed at the end of the witches wand. It grew bigger and brighter as the teacher concentrated all her magic on the happy thought. Suddenly, the Patronus changed and took on corporeal form. A silver, glowing winged horse made out of pure happiness reared, lighting the entire chamber before fading away.

"That's mine," said Merrythought happily. "Now lets see if the rest of you can produce anything. On your feet now! Find a space!"

As the rest of the students left their seats, Galatea turned to Buffy. "Think you can follow that? Don't worry if you can't. Patronuses are a strange and tricky piece of magic and you won't be tested for them on the NEWT exams let alone the OWLs. I just prefer my students knowing the correct incantation in case they ever need it."

Buffy shrugged a shoulder. "Everything's strange to me." She held out her yew wand in front of her and began to make the same circular motions the DADA teacher had demonstrated. Picking a happy memory wasn't so easy. It wasn't as if she had that many to choose from. She decided on her first one. The one where she'd dug herself from out of the collapsed building. Concentrating her magic and remembering the memory of those first rays of sunlight on her face, her first gulps of fresh London air, the taste of dust and soot in her mouth – all adding up to the amazing fact that she wasn't dead.

"Expecto Patronum!"

All the magic she'd held back burst from her core and something exploded from her wand. Unlike Galatea Merrythought's Patronus, hers was birthed fully formed. The creature beat its wings of blue-white light as it soared to the ceiling. Students let out gasps of surprise and exclamation as it swooped above their heads and leaving a trail of glittering light motes.

"Well done, Miss Summers! Thirty points to Slytherin!" Galatea Merrythought cried. She slapped Buffy on the back, taking her by surprise and almost knocking Buffy off her feet. "Magnificent first attempt my gel! I've never seen it done better. You mustn't forget to tell Dumbledore when you speak to him later. He'll be interested to learn the form of your Patronus and how you made a corporeal one on your first try."

…...

A/N ;-

Guess the Patronus? :-) Hint, it is something linked to Buffy. Let's see how many get it right.

So... Professor Merrythought wasn't that impressed with Buffy's knowledge. Now she has seen the Patronus she knows the girl has potential.

Did you spot Merrythought using a Disillusionment Charm to hide her from her students? The Slayer spotted her.

Thank you to all who have taken the time to leave a review.