A/N: This story just wouldn't let me go! I've wanted to see John meet Ianto for quite a while. I've got the whole thing written, and I'll be sure to post it when I've gotten in all typed up. I've planned it as a two shot, although it may expand into three parts. Although I've set it as John/Sherlock and Jack/Ianto established relationships, there isn't much romantic fluff. I don't see any of them as particularly sappy. Just because they're in love, it won't change any of their personalities. I guess that's all. Allons-y!

"Sherlock, I'm still not sure what we're looking for."

Cardiff. The Millennium Plaza. John Watson was shooting Sherlock Holmes an exasperated look.

"Hush, John. I need to focus."

John hushed. But inside, he was more than a little irritated. Being woken up at five to come to Cardiff was harsh, even by Sherlock's standards. He hadn't even gotten his morning cuppa, for god's sakes. He'd had to make do with the swill they served in the coffee shop at the train station. He wasn't much of a fan of caffeinated sludge, but it woke him up, and that was the main thing. He'd even got some of his patient records sorted while on the train, once he'd gotten used to typing against the jump and stutter of the rails. Even if this impromptu trip went completely down the tubes, the day would not be a total waste.

Still, he would have preferred it if Sherlock had taken some time out of the three hour train ride to actually explain what they were doing. He had prowled up and down the corridor of the train, scanning the other passengers carefully and muttering his deductions to John. John had followed him for a bit, but when Sherlock started loudly announcing which members of a certain school group were cheating on each other, John decided that it would be safer to hunker down in a car for a while to get some work done. After two and a half tours in Afghanistan and three years with Sherlock, there was still nothing that scared him more than an enraged teenage girl.

Well, maybe the smell of chlorine.

But anyways. Back to the present.

"Ah! I've got it!" Sherlock cried. He had been staring intently at the fountain for the past few minutes, but he appeared to have finally reached some sort of conclusion which involved grabbing John's upper arm and dragging him towards it post-haste. John wasn't even particularly startled. Sherlock only had two speeds; full throttle and full stop. He ricocheted between them suddenly and unpredictably, and usually John found it endearing. He was not in such a charitable mood today, however.

"What're you doing? Sherlock- Sherlock!" John tried to protest, but Sherlock ignored him. He stopped suddenly on a particular paving stone just before the fountain, and John nearly fell flat on his face. The detective had to grab his shoulders to keep him upright.

"For god's sakes, Sherlock, would you just explain-"

"No time for that, John! We have to be positioned just right, I believe." Sherlock gazed down at John's feet, one of which was partially on another paving stone. He shook his head, and, reaching forwards with his foot, kicked John's ankle until John moved the offending foot slightly forwards.

John wasn't entirely sure how a normal person would react to this situation. He was completely nonplussed, and if Sherlock had decided to take them all the way to Cardiff for another game of 'the floor is lava'...

Any further protests died on his lips as the paving stone began to descend.

"Wouldn't even know it was here, unless you looked hard enough." Sherlock said conversationally, as John tried to gather himself yet again. "Then again, no one ever looks hard enough. No one but me, that is. Or maybe Mycroft."

They were entering into a cavernous room, full of shining metal, stark concrete, and far more technology than John had ever seen in one place. And he had visited Mycroft's office. John shrugged off Sherlock's arms, still gripping his shoulders, and turned on the spot, trying to drink in as much of this curious place as he could. Then he heard a squawk from behind him, and turned around, and-

"Sherlock, is that a pterodactyl?"

Sherlock contemplated the creature. "Not sure. Maybe we should have brought Anderson."

John snorted.

"Yes, well, if it is a pterodactyl, we're in the right place."

The lift hit the ground, and Sherlock hopped off, while John followed more tentatively. The moment all four of their feet were on solid ground, an unmistakably Welsh voice said, "Freeze. Hands in the air."

Slowly, John and Sherlock raised their hands.

"We don't mean any harm." Sherlock called. John caught his eye, and grinned. Whether they meant harm or not, they could usually manage to make anyone's day a bit weirder. Although, seeing as how this Welsh chap spent his time in an underground bunker filled with technology that John was sure you couldn't buy at an Apple store, they might well have their work cut out for them.

"We're unarmed, Mr. Jones." Sherlock continued. John was sure he had somehow deduced the unseen man's name, and was now using it to unsettle him and gain the upper hand. One of Sherlock's favorite tactics, in fact. "Well, I am at least. I believe I've forgotten my gun at home."

"As always." John muttered.

"Yes, yes. My colleague, however, has a British Army Browning L9A1 in the back of his jacket. I believe he also has my gun in his computer bag, as well as a small bottle of mace in the cell phone pocket. Anything else, Doctor Watson?" Sherlock asked.

"Well, I suppose I could use my computer bag itself as a sort of bludgeon. And I've got my letter opener, that's rather sharp."

Sherlock scoffed. "Why do you have your letter opener? You haven't brought any letters."

"Sherlock, I know you've already deduced that I dropped it in there accidentally last night. Why do you bother asking?"

While they bantered back and forth, the elusive Mr. Jones stepped out from behind a tall glass and metal tower. He wore a headset, an impeccable suit and a scowl, and he held both a large device which looked to John like a GPS (but was clearly not) and a frankly impressive gun.

"Ah, yes. Hello, Mr. Jones." Sherlock said. "It's good to see you, however much I enjoy conversing with your furniture." Sherlock paused, tilted his head, and gazed at the stranger. He momentarily wore what John sometimes referred to as his 'deducing face'. The calculating expression was gone as quickly as it had come, though, and it was replaced with a smile that was clearly intended to be friendly. Clearly, Sherlock deemed this man important enough to attempt to get along with him. John straightened up. This Jones fellow must be very important indeed.

"You watch too many Bond films, you know." Sherlock continued. "You have a rather inflated sense of drama. Although that can be forgiven in your line of work." John didn't say anything to that. But Sherlock Holmes, of the giant flapping bat coat, telling anyone about their inflated sense of drama? The flaming hypocrite. John stored the moment carefully in his memory. He would most definitely want to bring this up later, when Sherlock was moping about the flat, whining about being bored.

Jones shifted his weight slightly, glancing back and forth between the two intruders. "Yes, well. You were honest about the weapons. So you've either got something we can't detect, which is unlikely, or you don't think you need them. Either way, you're to be reckoned with."

Sherlock looked pleased. "Oh yes, very good. You see, John? Not everyone is as dull as the imbeciles at the Yard. It's a pity Mr. Jones here isn't in charge, or our jobs would be quite a bit easier. Even if he is already in control of the entire operation, just by virtue of making himself vital."

"What operation, Sherlock?" John asked. "You still haven't told me why we're here."

"We're Torchwood." Jones said.

"Oh yes, very good, Mr. Jones." Sherlock cut in. "You can give us information with impunity, because you know you can just retcon us, don't you? Except you clearly don't know how I found out, or you would have stopped me. And you wouldn't be able to get it out of my head without erasing great swathes of memory, and you don't want to do that, do you? It wouldn't be right."

"We've done before." Jones said, but his brow furrowed, and his eyes clouded, and John sensed that this was bringing back memories the young man did not look upon fondly.

"Er, retcon?" John asked hastily, trying to steer the conversation in a more positive direction. "Erasing memories? I've never heard of Torchwood. Who exactly are you people?"

"Cardiff sits on a rift in time and space, John." Sherlock said calmly. "These people work 'outside the government and beyond the police', isn't that the phrase? They watch for aliens. If an alien shows up here, they find it and deal with it. Keeping the rest of the world in their happy ignorance."

"Hold on a second." John said. "Aliens? You mean, like little green men? Living on Mars, the whole bit? And these guys are, what, our interstellar tourist agency?"

"Crude but accurate." Sherlock agreed. "However, I don't believe there is anyone on Mars at the moment. Mycroft would have told me."

"Wow." John said. "Aliens. In Wales. This is... it's a lot to take in."

Jones frowned, and lowered his gun. "That's it?" he asked John. "He tells you that there are aliens, and you believe him, just like that?"

"I trust him." John said simply. And he did. Sherlock wouldn't lie to him, not like this. And if it was a lie, well, Sherlock must have a damn good reason for it. He knew John wouldn't be above moving to the upstairs bedroom for a few nights if it meant Sherlock would come up with a really good apology.

"Now that we've got that over with..." Sherlock said testily, "We'll be wanting a word with your boss."

"My boss?" Jones said.

"Yes, Jones." Sherlock said in his best 'don't be thick' tone. "Tall, dramatic fellow from the future? You're shagging him, so I certainly hope you can remember his name."

Jones went slightly red, and raised the gun again to cover this. "How do you know all this? Where are you getting your information?"

Sherlock rolled his eyes. "And I thought you were clever. It's obvious, isn't it? You've got the smell of rather strong cologne on you. Immaculate suit like yours, you wouldn't pick out such a ridiculous scent yourself. So, boyfriend. There's no other sign of him on you, so, someone you don't think it's appropriate to be with. Not a subordinate, no, you've only got five or six people working here judging by the number of workstations. There aren't enough of employees for you to have any subordinates. So, your boss. He outranks you, but a dramatic man who wears lots of cologne probably isn't the type to know the records back and forth like you do. He must have more field experience than you if you've not been promoted above him. But that isn't quite enough, is it? This is a rift in time and space; he must have come through at some point. If he knows earth well enough to keep you this well hidden, he's likely from here. Being from the past is pointless, that's what we have history books for. No, he's from the future. But not the distant future, just far enough away that he's got some impressive-looking knowledge. John!" he said, interrupting himself. "How long ago was the first recognizable human civilization?"

"Er-"

"A rough estimate is fine."

John reached back into the depths of his memory to his Year Eleven history class. When his poor teacher had tried to convince him that they were learning things that would be relevant to the world, he doubted this was what she intended. "Four, five thousand years, I'd say."

"There you go then, Mr. Jones." Sherlock said. "I'd estimate your boss, the elusive Captain Harkness, is from no further in the future than the year seven thousand. More likely closer to four."

"And how did you know that he was dramatic?" Jones asked. He looked impressed, despite himself.

"Mr. Jones. You are a quiet archivist who spends his free time reading files. You had to have learned that Bond impression from someone."

"Right on the money."

A tall American was descending the stairs behind Jones. He got to the bottom, and went to stand beside his coworker. For a wild second, John was reminded of a showdown, with two cowboys standing at a safe distance spitting insults and tobacco. Except there were two to a side instead of just one, and it wasn't the Old West but twenty first century Cardiff, and instead of six-guns and horses, they had lasers and a pterodactyl.

All right, so it was nothing like a showdown. That didn't stop John from moving his hand backwards to rest it on his gun. Better safe than sorry.

"I'm Captain Jack Harkness." said the American. "This is Ianto Jones. Who the hell are you?"

"I'm Sherlock Holmes. And this is Doctor John Watson, my colleague."

John did not miss the brief look of surprise that crossed the Captain's face before he schooled his features back to slightly less hostile neutrality. John exchanged a quick glance with Sherlock to confirm that of course the consulting detective had also taken note. Interesting. So the anachronistically-dressed American had already heard of them. John wasn't sure what to make of that.

"I believe you have had previous dealings with my brother Mycroft." Sherlock said. Again, another indicator as to the importance of these Torchwood blokes. Sherlock hated having to name-drop his brother, so the fact that he was doing it now showed that he didn't want to leave their good reception to chance.

"Yes, we owe quite a lot to Mr. Holmes." Ianto said, lowering his gun but not relinquishing it. John frankly was not surprised that Mycroft had dealing with aliens. He could probably relate to them quite well.

"Enough niceties, then." Sherlock said, and the Captain looked distinctly relieved. Enough time spent with Mycroft and his particular brand of protracted diplomacy could do that to you.

"We have reason to believe that Torchwood London is killing test subjects and disposing of them on the streets."

The relief on the Captain's face was gone as quickly as it had come. John didn't blame him. This must have been what Sherlock was working on for the past few weeks. There had been quite a few corpses found for which Sherlock had been unable to identify any possible suspects. He had been getting tetchier too, but John had chalked that down to his frustration at having failed. John hadn't suspected that he had been coming up with theories, but hiding them from the police. Although he wasn't sure he blamed Sherlock. John didn't want to imagine what Lestrade would say if they turned up in his office, talking about aliens. He felt sure it would involve straightjackets, though, and would probably make Anderson's day.

"What is your 'reason to believe'?" the Captain asked.

"There was mud on the shoes of all the victims, and it came from near Torchwood one headquarters, implying that the last time the victims had gone outside under their own power had been when they entered the building. They all died in very improbable ways, unless you factor in some technology which we will be theoretically able to create at some point during the future. One man had some slime on him, and the DNA in it didn't match anything I've ever seen before, and didn't appear to be from this planet, due to its complete evolutionary independence to any known creature. It was all there, you just had to look!"

"Sherlock, I don't think we can blame the police for not considering aliens as the cause of death." John chided him.

"John, when you've eliminate the impossible, whatever remains, however improbable, must be the truth." Sherlock said loftily.

"The last time you said that, you told me that the murderer was from a Balinese cult because you didn't realize that 'the angels have the phone box' is a quote from Doctor Who."

"Irrelevant, John."

"All right!"

John and Sherlock turned back to face Captain Harkness, who seemed as though he might have been amused at their bickering if they hadn't just informed him that members of his organization had been murdering innocent Londoners. "Holmes, come to my office. We can discuss this there."

Captain Harkness turned and strode up the stairs to his office, closely followed by Sherlock. Each on his own might have looked impressive. But the juxtaposition of both of their ostentatious coats side by side just looked faintly ridiculous.

Once they were both through the door and out of sight, he realized that he had just been left alone with a gun-wielding Welshman. He looked at Ianto apprehensively. Ianto smiled, and put down his gun.

"Tea?" he asked.

"Couldn't have put it better myself." John replied.