Disclaimer: Not mine. None of it is mine!

Author's Note: Ok, I got bored with only reading Doctor Who and Torchwood crossovers with Stargate, and I couldn't find this idea anywhere.

Set soon after Journey's End, and at some point not long after the episode of SG1 where Jacob Carter joins the Tok'ra. And we shall assume that the Doctor was lonely enough to allow Captain Jack to travel with him. Nothing more, mind you. I've only rated it at T, after all. That said, I am presenting most of this from Captain Jack's perspective, so. Yeah.

OC warning: Most of the Goa'uld, Tok'ra and slaves to the Goa'uld here are of my own creation, it was just easier this way. I wanted it to fit in with the main SG1 plot, rather than becoming AU. If I used existing System Lords it woulda gone AU.

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Chapter 1: Nameless

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"Earth? I thought we were going somewhere exciting and new?" Jack asked, glancing over the Doctor's shoulder at a readout he barely understood. And that was only because the TARDIS allowed him to understand enough of it to recognise that they were on Earth. Sometime in the late 1990s. That made what, three- four?- versions of him in the same time at once.

"We are." the Doctor said, blatantly amused at Jack's confusion, "It's just this is actually the best way to get there."

"Huh?"

"You'll see. Oh, and I'd not bring that if I were you." the Doctor hadn't even been looking at Jack, who had just picked up his sonic blaster. Jack slowly set the weapon down again. He didn't like going out unarmed, even if it was only Earth, but the Doctor usually knew best. Usually.

"Where are we, on Earth, then?" Jack asked, following the Doctor towards the doors.

"Cheyenne Mountain."

Jack froze, "Oh no. Not them, I've read the files!" he said, almost fearfully.

"What's the matter? This lot are nicer than Torchwood used to be." the Doctor said, teasingly.

"Some of them still believe in alien autopsies."

"Not the ones I'm here to see." and with that, the Doctor opened the doors and stepped out. He had stepped out into a corridor in what clearly was an underground base of some sort. Alarms were sounding, probably of the 'intruder alert' variety.

Jack stepped out after him, and they now both found themselves greeted by the business end of half a dozen rather large guns. He whispered in the Doctor's ear, "Still think I should be unarmed?"

"Yes." the Doctor said, a bit too brightly, holding his hands up in a sign of surrender.

At this point, another human poked his head out of a door down the corridor. He stared for several seconds, not at them, but at the TARDIS, then disappeared again.

"Identify yourselves!" one of the men with guns demanded.

Jack opened his mouth, but the Doctor elbowed him in the ribs, "Now is not a good time." he hissed, then he addressed the men with guns, "I'm the Doctor, this is Jack Harkness. We're not here to cause any trouble."

Jack idly thought that that statement almost guaranteed trouble would find him without his consent, but he decided not voice that opinion.

Then the man who had poked his head out of the door ran out towards them, "Lower your weapons!" he snapped. It was an order, though he seemed unused to or unhappy with the concept of giving orders. Jack could tell, he'd hung around the Doctor long enough to recognise the attitude.

The men holding the guns reluctantly complied. This other man looked younger than those he was ordering, though he had an air of experience they lacked. He was holding a very old looking stone tablet, which he now looked at, then up at the TARDIS and back again.

"This is probably a very odd question, but you wouldn't have ever been to a planet called Salaria, would you?" he asked.

"Lovely place, beautiful trees." the Doctor said, smiling cheerfully.

"About ten thousand years ago?" the man asked, in an ironic tone.

"Sounds about right." the Doctor said with a nod.

"Not many people get it this quick." Jack noted, then with his usual charming smile he stepped forward, "Hi, I'm Captain Jack Harkness."

The young man stared at Jack for several seconds, blinking as if slightly stunned by Jack's behaviour. Then again, Jack did come on to anything with a pulse just by saying hello. Finally, he spoke cautiously, "I'm Daniel Jackson. I'm the lead archaeologist here."

"And I'm the Doctor. Mind if I look at that?" he asked, indicating the stone tablet.

"Sure, no problem." Daniel handed said object to the Doctor.

After several seconds he handed it back to Daniel, "Yes, that was me."

Daniel's jaw dropped, "Wow." he muttered, "What are you doing here?"

"Need to trade for some supplies. And borrow some resources I know your lot have here." the Doctor said simply.

"I'm sure we could arrange something. The enemy of my enemy is my friend, after all." Daniel said brightly, "This way."

He started walking down the corridor, away from the TARDIS. The men with guns surrounded the Doctor and Jack as they followed.

"Do not point those things at me." the Doctor said, his tone warning. The men complied, albeit reluctantly.

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They were both subjected to a routine medical checkup, during which the Doctor made very dire warnings against attempting to take blood samples, but was quite happy to allow a scan to prove he did not have a 'Goa'uld symbiote', whatever that was. Jack reluctantly conceded to the same, only because the Doctor had done so first. The Doctor never let human medics anywhere near him if he could help it, so he must be taking this quite seriously.

Eventually, they were led to a briefing room, where they met with four new people.

One was an older, balding man with general's stripes on his military uniform, who was obviously in charge. Next to him stood another man, with grey hair and colonel stripes on his uniform, in which he seemed almost uncomfortable, as if he would rather be wearing combats instead of the dress uniform. A woman with short blond hair, and a rather large dark-skinned man with a golden emblem on his forehead that made Jack's skin crawl just looking at the design. The man himself also felt somehow wrong to Jack's senses. Not to mention, he had ominous glaring down to an art-form.

"General. These are the men we found in corridor D-6. I have a translation here of the ancient tablet that depicts their, um... ship?" he glanced at the Doctor, who nodded, seemingly amused at Daniel's confusion. "He's not human, but he'd definitely not Goa'uld. I'm not sure about this one here, he's also not Goa'uld, and seems human, but..."

"There is something unusual about him." the tall ominous one said. Look who's taking, Jack thought, though he didn't voice that retort.

"Doctor, Captain Harkness. This is General Hammond, Colonel Jack O'Neill. Captain Samantha Carter. And Teal'c."

"Just Doctor? No name, huh?" O'Neill asked.

"That's right." the Doctor answered.

"And they said they're here to trade for supplies and access to some of our, ah, acquired technology." Daniel added.

"What do you need?" Samantha Carter asked.

"A small amount of naqahdah. And the use of the quantum mirror." the Doctor said bluntly. Jack wondered what, exactly, a quantum mirror was, and why the Doctor seemed so interested in it. Or how this was supposed to take them to somewhere 'new and interesting', for that matter.

"And what do you have to trade for these?" the General asked. His tone had taken on a slightly hostile edge, as if he strongly disapproved of the idea of giving the Doctor what he was asking for, but he wanted to see where this negotiation was going before saying no.

"Depends what you want for them." the Doctor said, shrugging, "We could help you out with the Goa'uld, or we could offer other technology in trade."

"Wait, we are not giving them any of my technology." Jack interrupted.

"No, we're not." the Doctor agreed, "I was thinking alien, but closer to their own level than your toys."

Jack raised an eyebrow at the suggestion that his technology was just 'toys', and the Doctor rolled his eyes as if he actually got Jack's wordless insinuation about what he would really call 'toys'.

"Well, any help you could give us would be appreciated." Sam said.

O'Neil was reading the translation, "I think he should help out with the Goa'uld. If Daniel got this translation right, I mean."

"Of course I did!" Daniel said indignantly.

General Hammond read the translation, then nodded in agreement, "I think that would be the best arrangement."

"Alright, then." the Doctor said brightly, "Just don't expect me to kill them for you. That's a last resort, and I see it as a failure."

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"So what, exactly, did you do to earn their complete trust?" Jack asked, as they sat in the cafeteria. SG1, as Jack had learned the four humans- O'Neill, Carter, Daniel and Teal'c- called their team, were eating at the same table, and all seemed to be paying more attention to their visitors than to their food.

"Oh, I just overthrew one minor Goa'uld's little empire a few thousand years ago." the Doctor said dismissively.

"What are Goa'uld?" Jack asked.

"Alien parasites." O'Neill answered, "Mostly very hostile, like to play god."

"I've known a few beings liked to do that." Jack muttered, thinking specifically of the Master. And judging by the Doctor's glare, he knew what Jack had been insinuating.

"He didn't just overthrow that minor System Lord's rule on Salaria." Daniel interrupted, "He managed to extract the Goa'uld symbiote from its host without harming either of them. Convinced the Jaffa to cooperate with the humans, and instigated five thousand years of peace and prosperity on that world. The texts referred to him as the Nameless One. Most of the people on that world thought he was a real god, come to save them from the false gods."

Jack let out a low whistle. Five thousand years of peace wasn't half bad. Even if he didn't fully follow the remark about the Goa'uld symbiote. Was he to assume that was unusual? That if someone tried to remove the parasite it should normally kill the 'host'?

He never got a chance to ask the question, though, because a voice over the internal communications system sounded at that moment, "Unauthorised off-world activation!"

All of SG1 leapt to their feet, and bolted for the door. Jack exchanged a mildly exasperated look with the Doctor. Only to see that the Doctor returned it with a look of gleeful anticipation, before they both joined SG1 in racing towards whatever had caused that warning.

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Author's Note: Review, it makes me update faster.