Disclaimer: I do not own any of the characters mentioned herein, nor do I write this for any personal gain. All people and places in this chapter are the property of JK Rowling and Warner Bros.

A/N: The place and time here are the sort of ambiguous setting one would often find in a Mary Sue fic. This will probably take plot through book five into account, and I will take all facts established as canon including those revealed in book seven into account.

I wanted to do a serious and slightly dark take on Mary Sues here, so if you're looking for parody, I might write one later...

Dangerous Games: Prologue- "A Darker Dream"

There was a trace of vanilla scent in the air. The students half-contemplated this new smell while finishing their dinners and complaining about homework. As suddenly as it had come, the perfume disappeared, and everyone jumped as the sky and ceiling darkened rapidly.

Rain began fall from the ceiling of the Great Hall, and with it red rose petals. Dumbledore put a stop to this with a wave of his wand and a frown.

"What the…" Harry Potter muttered, but the rest of his words were drowned out in a deafening bang that sounded nothing like thunder. Everyone leapt from their chairs at the same time and began to stampede for the exit, ignoring the teachers' cries to behave in an orderly fashion.

"A dramatic entrance…" murmured Luna, as Harry, Hermione, and Ginny collided with her in the mass of people steaming from the Great Hall.

"What d'you mean?" Ginny asked, seizing Luna and Harry and dragging them to an empty corner as Hermione followed with her hand on Ginny's shoulder.

"A Mary Sue," Luna clarified. She paused patiently when Hermione made a small noise, as though she was about to add something.

Hermione opened her mouth to say something, found she had nothing to say, and closed it again. "Mary Sues aren't my area of expertise," she said stiffly, visibly annoyed about being forced to hand the job of explaining to Luna Lovegood.

"A Mary Sue is kind of like a patronus, but made of wish energy instead of happiness," Luna said dreamily.

"So it can't be that dangerous, can it?" Harry asked, feeling slightly relieved.

"Oh, no! A Sue is more dangerous than a nest full of nargles in October. That's their mating season, you know…"

Hermione made an impatient noise.

Luna seemed to pay no attention, but she continued. "A patronus is supposed to protect you right? That's what you said at the DA… Well a Mary Sue is supposed to attack. Muggles make Mary Sues to go after boys they fancy. It seems like this one was created by a bunch of girls at once, all pouring out their fantasies. Wishes are very powerful, Harry. That's why a Sue is so hard to get rid of…"

"Nothing a good hex can't take care of," Ginny said grimly, fingering her wand.

"Hexes won't work. No normal witch could match a Sue's powers! She's really persuasive, too! Dad says that your brain gets all fuzzy, and if she tells you to jump off a bridge, that's the end of you! And it get's worse because a Mary Sue is really beautiful, and she's more dangerous than a veela because she's created by people who are really determined to get what they want."

Harry shuddered. He had had plenty of experience with teenage girls who were obsessively determined to get what they wanted, and he didn't look forward to having the same experience with a creature with such formidable magical powers.

"So you'll have to be on your guard, Harry! If you know what's happening, you can stop it! Right?" Ginny said fiercely, balling her fists and closing her eyes. When she opened them again, she saw Hermione Granger's look of dismay. There was a growing trace of vanilla scent in the air.

"Harry? Harry!"

Harry Potter had run off, taking no notice of Hermione. The three girls watched his robes disappear around a corner.

Luna's voice was as calm as ever, but Ginny thought she detected a note of fear under the serenity. "It looks like it's too late…"

A/N: Review, please! Be sure to tell me how I can improve. And if you're wondering what happened to Ron, all will be revealed soon... probably around Chapter 2.