AN: I started posting this on my LJ more than two years ago, but never got around to finishing it. It's complete now, though, so updates will come very quickly.

This is set in SGA S5, with a S1 Dean thrown into the mix.

Don't own any of the characters or either of the shows, more's the pity. I'm just incredibly grateful for the creative minds who thought up the likes of Dean and Ronon so I could have my wicked way with them. What can I say, I'm a whumper and it shows.

Reviews would be awesome by the way. Just saying. :D

"Unscheduled gate activation," Chuck sang out as the symbols flashed around the Stargate. Richard Woolsey emerged from his office, a half eaten sandwich in one hand, while the other dabbed at his lips with a napkin.

"Who is it?" he asked in a somewhat muffled voice.

"It's Major Lorne's IDC," Amelia replied.

"Lorne? But they only left about fifteen minutes ago," Woolsey mused, clearly worried now.

"Incoming audio and video," Chuck announced.

All three turned to one of the monitors that sprang to life, showing Evan Lorne's frowning face. From his posture it was obvious that he was pointing a camcorder at himself.

"Major," Woolsey said, still clutching his forgotten sandwich in one hand. "Is there a problem?"

"Yes, Sir, you could say that. When we arrived at the lab we found all of the scientists dead."

"Dead?" Woolsey repeated, while Chuck and Amelia exchanged shocked glances. "But how…"

"See for yourself, Sir."

The camera panned away from Lorne and downwards. A figure in a white lab coat lay on the floor, mouth agape. It looked dry and shriveled, and its hands were clutching at its throat.

"Wraith?" Woolsey asked. Something about the body didn't quite fit with the usual appearance of the victims of these life-sucking aliens.

"Not sure, Sir. It's hard to say with the arms positioned the way they are, but as far as I can tell there's no feeding wound on the body."

"Have you searched the facility?"

"My team is combing the rooms as we speak," Lorne replied, turning the camera back onto himself, "but they've not reported any hostile presence. And the access portal was secure when we arrived, we only got in after entering the code. No sign of a forced entry."

"Gather all the evidence you can, Major, and report back to me. I will have…"

The sound of running footsteps interrupted what Woolsey was saying, and then they heard somebody off-screen gasp, "Simmons - he's… he's dead as well!"

"What?" The camera feed showed a wild sweep as Lorne turned towards the harbinger of these dire news.

"Just found him, Sir. Same symptoms as all the others."

"Where was he?"

"In the control center. He was downloading the footage from the security cameras. Here's his tablet."

Woolsey made his decision.

"Major Lorne, assemble your team and return immediately. That planet is off limits until we know what we are dealing with here."

Later

"Major Lorne was correct," Carson Beckett announced, slapping a pile of photos onto the conference room table. "No physical wounds on Sergeant Simmons to indicate a Wraith feeding, but the symptoms are very similar, except for a lower rate of desiccation. I'm baffled."

"You're just in time, doctor," Woolsey announced. "We are about to watch footage from the security cameras that was secured by Major Lorne and his team while they were on the planet. It may provide some answers. Dr. McKay?"

Rodney nodded and pressed a button on his tablet. A holographic screen appeared over the conference table. It was split into four sections, each showing a different lab with people in white coats working at their stations. Suddenly the scientist in the top left picture straightened, turned around and began to gasp. Tearing at his collar, he slowly sank to his knees and dropped to the floor where he lay writhing for a while before stilling completely. Soon after, the woman in the picture below began to hyperventilate.

"Hold it," Sheppard said, and the picture froze. "Could it be some kind of gas leak? A toxic substance that spread through the ventilation system?"

"It's a possibility," Carson admitted, "although I know of no substance that would reduce a human body to a shriveled husk such as this." He pointed at the photos he'd brought.

"And why would it affect only one member of my team and not all of us?" Lorne asked.

"Not to mention the fact," Rodney added, "that the air scrubbers in the compound are programmed to detect the slightest trace of pollutants. If there was a toxic substance, it would have triggered a subroutine of alarms as soon as it passed into the vents."

"It could be an alien substance the system didn't recognize." Sheppard wasn't willing to let go of his idea just yet.

"Nonono, you don't understand. The system is fine-tuned to a molecular level and reacts to anything it doesn't know." Rodney pulled a face. "In fact, it's so thorough we had to recall one chemist who was prone to flatulance. He triggered an alarm on more than one occasion. The methane…"

"Okay, Rodney, I get your drift," John interrupted, smirking.

"Shall we continue?" Woolsey suggested, and McKay re-started the playback.

"Whatever it is, it seems to move or spread from one room to the next," Lorne noted, as they watched the second victim fall to the ground, soon to be followed by a third who suffered the same symptoms as his unlucky fellow scientists.

"Stop," a deep vice growled. The image froze, and all eyes turned to Ronon. It was unusual for the Satedan to speak at these meetings without being prompted. His eyes squinted as he surveyed the screen. "What's that?"

"What's what?" Rodney asked, clearly annoyed a the interruption.

"That… haze hanging over the body."

All heads turned back to the screen.

"I cannot see any haze," Woolsey said finally.

"It is very faint, but I think Ronon is correct," Teyla countered.

"You sure you see something? Because I sure as hell can't," Sheppard stated.

"Actually, I've found that the people of this galaxy are blessed with especially acute eyesight," Carson volunteered. "And hearing," he added when Rodney muttered something under his breath. Ronon and Teyla exchanged a smirk.

"Yeah, McKay, right back atcha," the Satedan growled, causing the chief scientist to flush a deep shade of red.

"Let's continue, maybe it will re-appear," Lorne suggested.

"As far as I'm concerned it cannot RE-appear because it never appeared in the first…"

"Rodney," Sheppard interrupted, rolling his eyes. "Just push the damned button."

"Very well," McKay huffed, and the gruesome spectacle continued. As the last scientist sank to the floor, Rodney paused the tape again. For a moment there was silence around the table.

"I'll be damned," Lorne breathed finally, looking at Ronon with respect. The Satedan shrugged.

"Told ya."

"Okay, so there is something... cloud-like there," McKay countered with a 'big deal' expression on his face. "That still doesn't explain what happened to these people."

"It almost looks like a… ghost," Carson observed.

"Well, if that's what this thing is," Sheppard announced, "I know just who to call."