Disclaimer: I don't own Stargate Atlantis or NCIS, cause I am not rich enough... So, you know, hint... As in, no point doing anything about it.

Author's Note: So, I have had one of the best days! Cake at the ripe time of 12 AM, a good night's sleep, well, that just got it off to a good start. Working kind of sucked, but the happenings before it certainly made up for it. Got honked, in that good way, from a cute guy who used the whole, 'what's happening' eyebrow raise when I looked at him. Then my tax return went through, which means I actually could afford the deposit for a trip with uni to an archaeological dig in Italy middle of next year. And it's raining, but that's also a good thing! Cause rain is fun, cause it's kinda warm and it was still managing to hail, it ws awesome fun. And now... well, now I have chocolate and I've had red bull, which is probably the reason for this long intro...

So, anyways, I thought, what - besides the premiere of season 4 of Supernatural tonight and SGA tomorrow - could make this day even better? Why, posting this little crossover, of course!

But you would not believe how unbelievably hard to make up and then solve an investigation when your only training is television...

And now, on with the story! It's set season 5 SGA and earlier than season 5 NCIS, for those who care.

CROSS JURISDICTION

Chapter 1:

His bare feet thudded on the loose planks of the long, wide pier, making the entire wooden structure groan and shift as he ran as fast as he could along it. The night was dark, the stars hidden by storm clouds that made the sea tang in the air dissipate slightly.

But he noticed none of that.

He did notice the three sets of boots pounding after him. He noticed the splinters that sent tiny jabs of pain up through the nerve endings in his feet. He noticed the way his legs wobbled even as he ran, the drug pumping through his system making him unsteady and unstable.

He noticed the way he knew he was changing, noticed the greater feelings of rage and aggression, the way he thought less and less about how he had been kidnapped right out of his motel room by men so he could become their science experiment. He noticed he way he thought more and more about killing and hurting and destroying.

But he had somehow managed to retain enough of himself, enough of who he was, to know that he had to get out. So he had slipped his restraints – as a marine he was supposed to be good at these things – and he had run, escaping the dilapidated warehouse far enough ahead of some of the guards that he had begun thinking he had a chance.

Now, as he heard those guards getting closer, he knew his chances were slim.

Even as he dashed further from the warehouse, his breath hitching, his heart racing, his feet blurs in the night, they were getting closer. He could see the land end of the pier close by, the exact spot where wood met concrete. He knew if he could just make it onto that then the boxes and crates spread out on the raised concrete would give him shelter.

But apparently the guards chasing him knew that too.

It was as he leapt, aiming for the hard concrete a foot above the pier, that the shots called out, all three guns firing simultaneously. He was shoved forward, three white hot spots flaring in his back as he fell face down onto the concrete, entire body going numb as heat flowed from and down his back, down his sides to spread out in a pool about him.

The world blinked, and then greyed, the night seeping in from the corner of his eyes to leave the world black. And then he fell into death.

"What are you thinking?"

Ziva David looked up as McGee came to stand next to her before the plasma, upon which photos of their latest crime scene were displayed. The marine shoved uncaringly into a corner of a back alley downtown was bare-chested except for his dog tags identifying him as Private Zachary Merton. By all accounts it looked like he had been mugged – his wallet, phone and watch were missing – but Ziva had been investigating crime scenes long enough now to know just how deceiving looks could be.

She shook her head in reply to McGee's question. "Just that the person or people who did this… They did not seem to care about what they were trying to make the scene look like. They came up with an idea but could only be bothered to create the most basic disguise for what truly happened."

McGee nodded, staring at the photo with her. "I know what you mean. What mugger takes someone's shirt? Or shoots someone in the back three times? Besides the fact that there's not enough blood in the alley for that to be the place Merton was murdered, there's a whole bunch of things wrong."

"Like what, McGee?"

Both Ziva and aforementioned probie jumped at the sound of their boss just behind them, the Mossad agent spinning to face Agent Gibbs while McGee turned somewhat more slowly, a startled look still on his face.

"Uh, like… I mean, the fact that he was moved." He looked to Ziva as if asking for help, but she just grinned and let him continue on his own. "The fact that it looks like someone dressed him in those jeans after he was dead. There's not enough blood on them otherwise. Even though he was shot in the back, he's sitting down, with his back against the wall." He was getting into a rhythm now. "And then there's the bruises around his wrist, as if he was restrained."

"And of course," Ziva added, pressing a button on the remote and moving to a picture of his elbow. "There's the needle marks, a dozen of them all from the past few days." She turned to Gibbs. "Abby's running a blood test now. She should be able to tell us what he was taking."

The greying NCIS agent nodded, which was about as much praise as either of them had come to expect. Turning away, he looked at the desk to his right. "Where's DiNozzo?"

Ziva and McGee turned to look at the desk as well, before the Mossad agent checked her watch. "He's -."

"Back," the final member of the team called out as he walked past the dividers that separated work stations. "From getting what information he could from Merton's fellow marines."

DiNozzo dumped his bag on his desk and turned to face the others as they waited expectantly. "I spoke to Private Merton's unit, and also a Staff Sergeant Jackson. Apparently Merton was on leave after a tour in Afghanistan. He'd only been back nine days. So I went to Merton's motel, the manager said he'd checked out over a week ago. Or rather, a girlfriend of his did."

"A girlfriend?" Gibbs asked with more than a hint of disbelief. DiNozzo shrugged and leaned back against his desk.

"That's what I thought. Especially after I remembered that Staff Sergeant Jackson and various other marines had told me that outside the marines, Merton basically had no life. Troubled childhood, a few offences, court appearances… he always claimed the marines turned his life around. His unit didn't know of any girlfriend, family, or even acquaintances outside the army. So I got a photo of the girl from security cameras, but she paid in cash, so no credit card.

"I asked the manager when the last time he had seen Merton was, he said eight days." He looked at the photos on the plasma, before moving around his desk to sit at his computer. "There was nothing in his room that I could see. No blood, no sign of a struggle. There was another couple already in there, so it was hard to be sure, but either he left without resistance or without being conscious."

Without a word, Gibbs turned and left, and his team moved back to their desks to get working on the case, used to his abrupt manner, taking no insult from it. It was juts Gibbs' way.

Agent Gibbs thought nothing of it either. He just walked to the elevator at the back and made his way down a few flights to the lab where the NCIS forensic expert worked. He only made one stop on the way.

For once the music was almost bearable, and turned down so low it didn't really matter. Abby, in all her gothic glory, was clearly waiting for him, a huge smile on her face. It only widened as her eyes fell on the Caf-Pow in Gibbs' hand.

"You're slipping, Gibbs," she told him, still eyeing off the huge drink in the man's hand. Eyeing her, grinning inside, he held the drink back.

"How so?" he asked, watching her squirm as he didn't hand over the caffeine-heavy cup. Her eyes flicked from the drink to Gibbs.

"Well, I found something out a few minutes ago," she told him, getting edgy now. "Usually you're here after only seconds. I was just thinking I might have to remember the number for your office."

Eyeing her carefully, Gibbs smiled and handed over the Caf-Pow. "I was just about to come down here when DiNozzo returned," he told her. "So, what do you have?"
She took a long draw through the thick straw and turned to her computer, shaking her head and getting down to business. Gibbs came to stand beside her, though there was no way he was ever going to understand more than a fifth of the technical words spread over one of the screens.

"What do I have?" she demanded, looking at him as she placed the Caf-Pow aside. "That is a very good question, Gibbs. I have… blood tests, bullet fragments, fragments of some other kind that Ducky pulled from Private Merton's feet that I'm analysing right now. Well, not me, but my machine…" She trailed off as she saw the look on Gibbs' face. "So, blood test first?"

Gibbs nodded and she tapped away on her computer. "Good, because that's what I just got results on… and it's more than a little hinky."

"Why?" the agent asked, staring at the screen, even when he wasn't sure he could even pronounce the words on the screen, let alone say or use them.

"Well, we can say for sure it's Merton. And he was being drugged. Or was taking them. That's up to you to decide. Either way, he had a rather strange cocktail in his system. It's got some of the… usuals in it – steroids, rage-inducents, as well as a few suppressants…"

"That's usual?" Gibbs demanded, looking at her and then looking at the computer again. "Cause that's not in any tablets I ever take."

"It's usual when you compare it to what else was in there," she told him rather darkly, shaking her head. Her black pigtails moved with it.

"Why?" Gibbs asked. "What was in it?"

"I don't know," she told him, her voice gathering pitch. She seemed rather devastated by it. "It's from something living, because it has DNA in it. But my computer couldn't tell me what the DNA belonged to. Didn't have a clue. Wasn't even close to anything in my database. And I have everything in my database."

Gibbs frowned, and stared at her. "So what, some kind of venom, or poison?" he asked, a little confused. She shook her head again.

"No. At least, I don't think so. Look, the whole thing, it's very, very advanced, whatever it is. And if I had to make a guess, I'd say that the drug given to Merton over the time he was… missing, I guess… I'd say it was some kind of gene therapy. Experimental gene therapy if the various levels he was given are any sign."

Gibbs' eyebrows climbed, and he looked at the computer, squinting slightly as he focused on the words. "That's pretty dark," he told her, leaning back and thinking. "So Private Merton was kidnapped to be experimented on."

Over in Colorado, beneath Cheyenne Mountain, the Stargate, a secret from the vast majority of Americans, including most of their government and armed services, activated in a sudden horizontal vortex, before snapping back in and rippling slightly within the ring.

A minute later, identities confirmed, the lead team for the Atlantis expedition to the Pegasus Galaxy stepped through, small bags in their hands, grim looks on the faces of the two originally from Earth.

Lieutenant Colonel John Sheppard led them down the ramp, greeting Generals Landry and O'Neill where they waited at the bottom. O'Neill took the lead, speaking while Landry watched on.

"Colonel Sheppard, sorry to pull you away from your duties on Atlantis." He nodded at the three behind the pilot. "McKay, Ms Emmagen, Mr Dex. Happy to have you."

"We heard you have a small problem, sir," Sheppard said, moving off the ramp as the Stargate shut down. "And we're happy to help out."

O'Neill nodded. "Good. Let's get to it then. We haven't got much time. We're going to brief you, and then Colonel Ellis is waiting to beam you up. So, let's get this done."

They all moved to the conference room, handing their bags to the two lieutenants who came to grab them. Taking their seats around the table, General Landry began the briefing.

"A few months ago, one of our scientists at Area 51 quit his job and walked away. We've been keeping an eye on him, or we were. One month ago he disappeared, and it was around that time that we found out some of the material he had been working on was missing."

"What was he working on?" McKay asked, taking a long drink of water. O'Neill spun on his chair and avoided looking at Sheppard as the pilot leafed through the report he had found in the middle of the table.

"Iratus bugs," O'Neill told him, and Sheppard winced, looking up, utter disgust on his face.

"I hate those things."

"Your dislike has been noted," Landry told him, gesturing at the reports remaining on the table. The other three team members grabbed a copy and opened the folder.

"Hmm," McKay said as he did so. "It's been noted several times."

Sheppard glared at him. "I'd like to see you have one attached to your neck," he spat, before turning back to his superiors. "So what does this have to do with us and a dead marine?"

Rodney looked up and mouthed 'dead marine' before looking quickly through the report. Landry turned on the plasma and let the images of the dead marine fill the screen. McKay groaned.

"We just got a hit from a lab belonging to NCIS," Landry told him. "Because it's a marine, they picked it up. And this marine was being drugged. With something that had Iratus DNA in it."

The team exchanged dark looks. "So this scientist is attempting to create his own hybrids?" Teyla asked, just to make sure they were all thinking the same thing.

"It would appear so," Landry told them. "Which is why we called you in. We need you to take over this investigation. NCIS agents do not know about interstellar travel. Or alien bugs from planets in other galaxies."

He turned the plasma off and turned to Sheppard. "The Apollo will beam you down to Washington so you can go to NCIS headquarters and take over this investigation from an Agent Gibbs," he told the pilot, handing him a folded letter. "Make sure you get all their information, data, evidence, to take back to the Apollo. We need to catch this scientist and whoever he's working for. And international security needs to be maintained." He glanced over them, then frowned, taking in Ronon's outlandish clothes and the Atlantis uniforms of the others. "After you get changed, of course."

"What have you got, Ducky?"

The short medical examiner looked up from where he was washing his hands as Gibbs entered the morgue, followed by DiNozzo and Ziva, who appeared to be annoying each other once more. They stopped as they entered the morgue, falling silent at the sight of Merton lying on the cold table.

Dr Mallard, affectionately known as Ducky to everyone at NCIS, turned as the three agents entered and walked over.

"Something of which the likes I have never seen," he told them immediately in his rich accent. "I have to say, Jethro." Jethro being Gibbs. "I have never autopsied a body like young Private Merton."

DiNozzo moved closer and leaned over. "Looks pretty standard on the outside," he spoke up without thinking. "I mean, as far as dead bodies go."

Gibbs went a little stiff but didn't say anything to his agent. Instead, he turned to Ducky. "What's different about him?" he asked.

Ducky shook his head. "Whatever was in his system had dramatically changed his physiology. His muscles were bigger than any I have ever seen in a man his size, even for a marine. But with the dosages he was on, there were far more changes for the worse."

He moved over to a light board and switched it on to illuminate the x-rays of Merton's chest. "His lungs were rather shrunken. His heart was close to giving out before he was shot. And… I can't believe I'm going to say this, but his bones appeared to be mutating."

"Mutating?" Both DiNozzo and Ziva demanded, the former moving quickly away from the corpse. The Mossad agent spared her colleague a disparaging glance before continuing. "Mutating how?"

"It's hard to explain," Ducky told them, obviously struggling to get the words out. "But his bones were… bending, I suppose you could call it. I'm not sure what the end result would be."

Gibbs let that sink in. "So, was he killed by being shot?" he asked.

Ducky nodded. "He was. Abby should have the results on the three bullets now. But I can tell you some things for sure," he added, turning the light off. "Someone put those shoes on him. He was running from someone, or I assume he was. He had splinter sized shells and wood embedded in his feet. And he was being restrained, for a few days at least. Those bruises are new overlapping old. Continuous. And he had a dozen needle puncture marks in his right arm, all ranging from six to two days old."

"So he wasn't there by will," DiNozzo stated the obvious. He stood up straight and answered the inevitable question. "McGee's running her photo right now, Boss. The picture was pretty clear, so if she's in the system we'll get her."

Gibbs nodded, and then gestured a little violently at the door. "Well. Go see if there's anything there already."

DiNozzo nodded and left, while Ziva moved closer. Gibbs turned to Ducky. "Anything else I need to know?" he asked. Ducky gave a small, non-committal shrug. "What is it, Ducky?"

"Nothing pertinent, I believe. I mean, those bullets definitely killed him."

"But?" Ziva asked, both her and her boss hearing the unsaid conjunction. Ducky sighed and took his glasses off, looking perplexed.

"But, I do believe that if he hadn't been hit by all three bullets, he would not have died."

Lots more of our favourite SGA team next chapter!