Chris Carter and 1013 Productions own the X-Files. JK Rowling, Warner Brothers and Scholastic own Harry Potter. All I own is this story line, every Harry Potter DVD and a complete collection of X-Files DVD's. I wish I owned Fox Mulder.

A/N This story is set anytime during Sorcerers Stone through Prisoner of Azkaban of HP (although it contains information in all the books) and after X-Files episode "Emily", but before "Requiem".

Thanks to all you wonderful reviewers!

POTIONS CLASSROOM

HOGWARTS

The next morning, Scully was sitting in her usual place during the Potions class when the student catty-corner to her got splashed with a boiling liquid and cried out "ouch!" Immediately she slid off her stool and reached over to turn on the faucet. As the icy water poured out through the gargoyle's mouth, she headed to the student. Pushing his sleeve up over the site, she saw that it was already starting to blister and she turned to lead him over to the sink when Snape appeared with an antidote.

"I have it," he muttered and administered a few drops of the potion onto the wound. Then he waved his wand over the injury and started saying the incantation. Their eyes met over the head of the student and Scully slowly walked back to the sink, turned off the faucet and settled herself back on her stool.

As he resumed his lecture, out of the corner of his eye, he could see her looking at him as he taught, and she could see him looking at her as she sat writing busily with her pen.

HEADMASTER'S OFFICE

THAT AFTERNOON

Later that afternoon they received a summons from the Headmaster and joined the others in Dumbledore's office after class.

"We've received the report back from your Mr. Frohike," Dumbledore said.

Mulder was looking over the pages. "Apparently, the chemical analysis from the ceiling pieces revealed a small amount of two substances. These precise compositions are not found in nature, but they are very similar to phosphodiesterases and hyaluronidase. Do you know what those are?" He asked.

Scully nodded slowly. "Yes, Mulder, they're found in snake venoms. The phosphodiesterases lower the blood pressure and hyaluronidase increases tissue permeability--it makes the venom work faster, in other words."

"They were only in the fault line where the ceiling broke off--the control sample showed nothing out of the ordinary," Mulder continued as he handed the report to Scully, who looked at it intently.

"Snake venom was in the ceiling?" Asked Snape, startled.

Scully shook her head, frowning at the pages. "Not precisely. What was found in the sample are chemical analogs,"

"What does that mean, Agent Scully?" Asked McGonagall.

"That they are structurally similar on the molecular level."

"So now you're saying there was some sort of poison in the ceiling?" Pressed McGonagall.

"Not necessarily. While they are structurally similar--well, look here--" she said, pointing to a diagram on one of the papers. "This is the part of the molecule that's different, and the difference could cause the chemicals to have an unexpected effect on the body, an opposite effect or even no effect at all."

"So, it appears that the entity that attacked us left this chemical marker behind," added Mulder.

"But is it dangerous if the substances are still in the ceiling?" That question came from Dumbledore, but Scully suspected he already knew the answer.

"Naturally occurring snake venoms have to be injected into the body," she said, looking directly at the Headmaster. "There would be no danger from merely being in the same room with it."

"Is there any way of knowing for sure how these chemicals would affect a person?" Asked McGonagall.

"Without testing them, no. And that's not something we would want to do, for obvious reasons."

"There's also the question of who would be an appropriate test subject," Mulder mused.

"What do you mean?" Scully asked.

"What if the difference between wizards and muggles is in biochemistry or genetics?"

Scully looked at him, eyebrow raised, but he continued. "If whatever it is that makes the wizarding population capable of magic--if it's actually something on the molecular level, then chemical agents might work differently depending on whether it's a wizard or a muggle who's exposed to it."

"But why snake venom, Mulder? What's the significance of that?"

"It's known that Salazar Slytherin could speak to snakes--the skill is called parseltongue--Voldemort could also do it," replied Dumbledore.

"Did You Know Who keep a snake as a familiar?" Mulder asked him.

"I don't know, but you reported there was no evidence of a corporeal entity."

"What are you getting at, Mulder?"

"Well, Scully, the ancient shamans believed that the spirit of the snake aided exploration of the mysteries of life and immortality. Through the snake the shaman could travel to the spirit world."

"There are plenty of ghosts here. You know who wouldn't have to travel to the spirit world to find them," she said dryly.

"But explorations of immortality--that was something he was interested in--obsessed with, actually. The evidence is getting stronger in the direction of Voldemort." Dumbledore looked pleased, although not surprised by anything that was said today, Scully thought.

THE GREAT HALL

LATER THAT NIGHT

"It feels confining not being allowed outside after dark," Scully said. "And yes, I know it's for security reasons."

"Looking through the ceiling of the Great Hall is like looking directly at the outside," Snape replied. "We can go there after rounds."

When his rounds were completed they went into the Great Hall. It was dark and gloomy with only a few torches burning, but the nighttime sky was clearly visible. Scully sat down on one of the benches to see the view.

"Do you find that muggles react differently to potions than do your people?"

"I don't make potions for muggles. But it's well known that some potions do react differently. Things are--"

"Different here. Yes. You already said that." Sighing, she stood up and walked slowly towards the dais where the faculty ate. "You know, I can never look at the stars anymore without wondering if they are up there and what they're thinking."

"'They', Agent Scully? Who are 'they'?"

"Just look up, Professor Snape. Did you know that scientists have discovered planets rotating around some of those stars?"

"No..."

"Surely there must be life on some of them. Maybe even intelligent life. Intelligent enough to look into their sky, see our star and wonder if there is anyone here wondering about them there."

"People from other planets?" He scoffed. "Surely no reasonable person believes they exist."

Scully gave a dry little chuckle. "And where I come from, most people wouldn't believe you exist." She turned to look at him. "That sounds flippant. But, think about it. You've all done a good job of hiding yourselves." Scully pressed on. "Don't any of you believe there might be extraterrestrial life?"

"We don't really give it a second thought. We have other, more pressing concerns than to wonder about what's going on other planets. But no, I don't think most of us take that notion seriously. We just dismiss it as silly muggle superstition. "

Scully laughed mysteriously. "A few years ago I was assigned to investigate the X-Files--the unexplained cases. I was supposed to prove them all as hoaxes, as the products of overactive imaginations. But, I wasn't able to. Furthermore, I learned a little more than was good for me. And yes, I've seen evidence of things that were very hard to explain away. But the most disturbing thing of all," She sat down on the dais and looked at Snape with a serious, intense gaze. "Is that there are people who are willing to kill randomly and without remorse to hide their secrets." Unconsciously, her hand went to the back of her neck. "Sometimes they are people you always assumed were on your side."

"That happens here too." He said as he sat down next to her. "You can't always be sure who's working against you."

"I thought you said things were different here," she said, quietly.

"I did say that. But some things are the same." He leaned towards her then, and this time they weren't interrupted.

Thanks for reading. Of course, if you read this far there must be a reason. Please review and let me know what that reason was!