"I'll need a volunteer."

“...so, as you can see, there’s a long list of ways to test if somebody is a witch,” Amy says. The study hall is mostly full now. Around fifteen or twenty students sit in the chairs, listening more or less intently. Most of their faces are familiar. Meg knows a few well, is passingly familiar with several others and has never spoken to the rest. “And they were all actually used historically! Now, for this next part, I’ll need a volunteer.”

“Sitri?”

“Yes, Meg?”

“Pull her panties down.”

“Right away, Meg,” you say, and count invisibly to ten. “Hmm. Meg, I have some bad news for you.”

“What? What do you mean? Hey, I’m supposed to be able to pull girls’ panties down whenever I want! You can’t change the rules on me like that!”

“Remember when I said there was a dark ancient magic loose on this campus?” you say to Meg. Of course, you’re using your powers to render the conversation inaudible to anyone else. “Well, I think she has some of it.”

“Her?”

“Don’t get too freaked out, Meg, but I think she might be… a demon!”

“Another demon! Oh, no!” Meg has of course only met Amy on her nightly trips to Hell, which she only remembers during the day as a nagging subconscious feeling that somebody somewhere is getting one over her. “What are we going to do, Sitri? Can you stop her?”

“I’m not sure. It seems like she’s a very ancient and powerful demon.” This is technically true, since all demons are very ancient and powerful, but of course she’s not even the tiniest fraction as ancient and powerful as you. But Meg doesn’t need to know that. “And, Meg, you need to know I’m not the only demon who likes playing pranks on girls. All demons like it, actually.”

“But, Sitri, I’m a girl!”

“In that case, you may be ****. You’ll have to be careful. Now, Meg, I need to tell you something important. There’s one thing you need to do if you want to be immune to demonic pranks. Listen very carefully. As long as you do this one thing, you’ll be safe.”

“What is it, Sitri? What?”

“All you need to do is… oh, no! She’s expelling me from the mortal plane! I’m being sent back to Hell! Stay strong, Meg! I’ll come back to save you, just as soon as aaaaaahhhhh!” You make vacuuming sounds with your mouth, pretending to be sucked across dimensional barriers, and become even more invisible, so now Meg can’t see you.

“Meg?” Amy’s looking directly at her. Beth’s already standing up. “Are you paying attention?”

“I… yes, ma’am,” says Meg, and realises she’s just called the teacher “ma’am”. The class sniggers as she hastily stands up as well. Amy beckons her forward.

“Thank you so much for volunteering,” she says, brightly, as Meg and Beth are brought to stand together at the front of the class. “I’m sure it will be good for the participation component of your grades. Now, class, I’m going to demonstrate perhaps the most famous way to test if a woman is a witch, which is to find the witch’s mark somewhere on her body. Of course, it’s often hidden, so you have to look rather carefully.”

“Eep.”

“Girls, please take off your tops.”

Meg and Beth stand before the class in their bras and skirts, suffering through the giggles. Amy makes them raise their arms, and conducts a painstaking visual inspection of every area of exposed skin. “Nothing,” she says, presently. “But you’re not out of the clear yet, girls. Skirts off, please.”

More giggles at the skirts hit the floor. Amy carefully examines the red-faced girls’ legs, their hips, even the soles of their feet. “Still haven’t found the witch’s mark,” she says, cheerfully. “But it could be hiding anywhere. Bras, please!”

“Excuse me, Amy, please,” says Beth. “I don’t want to have to volunteer any more.”

“Backing out halfway through a live demonstration is terrible for your participation grades, girls. But you don’t have to be worried. This is an academic environment. Nobody’s going to think anything unusual is going on.”

Bras are reluctantly unclasped. Meg and Beth stand with their arms raised while Amy lifts up both pairs of breasts, Meg’s small ones and Beth’s big ones, to check if the witch’s mark might not be hiding on their lower curves. “Still a few places we haven’t looked,” she says, cheerfully.

“What if I just really really really really really promise I’m not a witch?”

“That’s just what a witch would say!”

The growing pile of Meg and Beth’s clothes on the floor beside Amy is crowned by two pairs of panties, Meg’s yellow and Beth’s adorned with cute Space Invaders pixel art. “Turn around, girls,” says Amy, presenting their bare buttocks for the class’s visual inspection. “We even have to check between the cheeks, here…”

“Ahh!”

“Only one spot left to check,” says Amy, turning the now brightly-blushing girls around again. “Now, remember, it can be really, really, really well hidden. Why don’t you do the honors, girls?”

“Um… what do you mean?”

“Go ahead. Prove you’re not witches.”

“Actually, we are witches,” says Beth. “So you don’t need to look. We’re both witches, you caught us, well done, can we go?”

“Great, we caught some witches! I’ll go get the scold’s bridle and the ducking stool and you can see some traditional witch punishment!”

“No, wait, we’re not witches, I was joking!”

“Well, you’d better prove it, girls. Go on, don’t be shy. Countless women all across Europe had to do this. Often in front of the entire village!”

“But… but… yes, Amy.” Meg’s and Beth’s hands move slowly down between their legs. Reluctantly, hating every second, the girls part their pussy lips with their fingers and stand before the class, legs spread wide, allowing all their classmates to see every intimate inch of their velvety-pink and undeniably dripping-wet vaginas. Heads crane forward to see.

“Perfect! Stay like that, girls.” Meg and Beth are both now blushing so hard they can’t produce any sound above a whimper. Amy reaches into her bag and, with an evil smile on her face, draws out a long black feather.

“Now,” she says, “the witch’s mark isn’t always visible to the naked eye. But there’s one test that never fails. It’s the only spot on a girl’s body that isn’t ticklish.”