Title: Smokescreen
Part: 1/10
Fandom: SG-1/Atlantis cross-over.
Pairing: Sam/Jack
Genre: Sci-fi, adventure, some hurt/comfort
Season: Four of Atlantis (between Trio and Midway)

Summary:
With random offworld Gate activations and signs of an intruder in their midst, Carter and Sheppard are trying to conduct an investigation as subtly as possible – but then Jack O'Neill arrives.

A/N: Inspired by a deleted scene from Trio, in which Sam tells Jennifer that "it's complicated" with a guy back in Washington.


PART ONE

In her office overlooking the Stargate, Colonel Samantha Carter was trying to get some sense out of two of the brightest minds on Atlantis.

"There is nothing wrong with it," McKay was saying, jabbing a finger towards the Gate.

"Not yet," Zelenka shot back, his native Czech accent thickening slightly in his anger. "But who knows, since you've been fiddling around with the shield generators?"

"I have not been 'fiddling around.' I've been conducting tests, not that you'd know the difference between the two."

"Hey!" Sam interrupted, raising a hand to silence them. "Do we know what we're dealing with here or not?"

"We're not dealing with anything," Rodney answered. "It's Zelenka, he's seeing things."

"I am not!" Zelenka replied heatedly. Sam folded her arms and leaned against her desk.

"Radek, what's your assessment?"

Zelenka shot a disdainful glance towards McKay before explaining: "There is a minute increase in the shield read-outs."

"Oh, what," Rodney scoffed, "like, half a percent?"

Zelenka glared at him. "Half a percent over absolute maximum capacity, Rodney. It could indicate the beginnings of a power build-up within the Gate."

"There's nothing there!" McKay insisted, gesturing emphatically. "There's probably just some residual energy registering on the sensors!"

"Okay," Sam called, raising her hand again as Zelenka opened his mouth to give a heated reply to McKay's words. "Let's back-track. Sixteen hours ago, we received an unscheduled offworld activation. The wormhole was sustained for its maximum of thirty-eight minutes with no incoming traveller or transmission, which as far as we know should be impossible. We've been receiving similar activations ever since." She looked between them. "Apart from this apparent increase in shield power, what have we got? Anything?"

"Well... no," Zelenka admitted.

"It's like I've been saying all along," McKay answered. "An offworld Gate must be malfunctioning. Somewhere along the line, we gated back from a planet, somehow the DHD got screwed up, now it's dialling us back at random intervals. It's the only explanation."

Zelenka muttered something in Czech, to which McKay replied, "Hey! Sam asked for ideas; I'm giving her an idea!"

"Now, that's enough," Sam told them. "There isn't any immediate evidence for either claim. What I'm more worried about at the moment is making sure there isn't any immediate threat. The defence teams are on alert but it's up to your departments to monitor the situation. Check all energy and radiation levels and compare them with the base data. I also want to know if there's anything on the long-range sensors – and get Chuck to compare the number of life-signs on Atlantis with the personnel roster. And if the Gate activates again I want you to run all those tests again."

"Sam, look, this really isn't..." Rodney began, but at Sam's look he trailed off.

"It's necessary, Rodney," Sam told him.

"Right," he answered. Taking that as their dismissal, he and Zelenka turned and headed back towards the Control Room, passing John Sheppard on the bridge. He greeted them briefly before continuing on to Sam's office.

"Having trouble with the kids?" Sheppard asked with a slight smile on his face. Sam sighed and sat down behind her desk.

"Close the door, John."

Sheppard waved a hand over the sensor on the wall; the glass door slid shut behind him and he moved forward to sit down. "I take it you're still concerned about a security breach, Colonel?"

Sam glanced momentarily towards the Stargate. "Yes, I am. The fact that we're receiving apparently random offworld activations with nothing incoming would be unsettling enough – but with evidence of someone trying to tamper with some of our security systems as well..."

"We may already have hostile activity on Atlantis," Sheppard agreed. "Does anybody else know about what Chuck found in the security log?"

"No. Until we know more about what's going on here, I don't want to let on that we're aware of anything more than the unusual Gate activity. But I do want your team to investigate. I need McKay to be working on the problems with the Stargate, but take Teyla and Ronon and see what you can find out."

"Sure, Colonel. I'll–"

He was interrupted by the alarm as the Stargate activated. Sheppard and Carter exchanged glances and hurried out of the office towards the Control Room.

"Incoming wormhole!" Chuck warned as they arrived.

"Another phantom activation?" Teyla enquired.

"Looks like," Sheppard replied, but a second later Chuck said: "Receiving Midway's IDC."

"Midway?" Ronon asked. "Are we expecting anyone from them?"

"Lower the shield," Sam ordered. "Defence teams, hold position."

She made her way towards the wide staircase that led down towards the Stargate as the shield disappeared from over the event horizon. When the traveller emerged, Sam halted half-way down the stairs out of sheer surprise.

"Sir!" was all she could think of to say.

Jack O'Neill cast a fond glance over his shoulder at the Stargate before turning back to give his old second-in-command a cheery smile. He was wearing Air Force dress blues, with an incongruous red-and-white baseball cap covering his grey-silver hair, and was carrying a black hold-all bag in his right hand.

"Hey, Carter," he said. "How's it goin'?"

She couldn't help but return his grin. As the Stargate disengaged, she resumed her descent of the stairs to greet him; behind her, Sheppard and his team followed suit.

"This is... unexpected," Sheppard remarked as they reached O'Neill; but Jack was still looking at Sam, a wry smile on his face.

"Defence teams, stand down," she said. Around them, the armed soldiers lowered their weapons and began to disperse. "Colonel Sheppard's right, sir," she added to O'Neill: "we weren't expecting you."

Jack's face fell. "The visit?" he asked. "The morale-boosting visit that's been months in the planning?"

"That's today?" Sam closed her eyes briefly, lifting a hand to her forehand. "I'm sorry, sir. I completely forgot. We've been dealing with a few things and..."

"You're the high-flying dignitary?" McKay interrupted incredulously. "What happened to the presidential visit?"

"There was never going to be a presidential visit, McKay," Sheppard returned.

"But they never told us who was coming, I just assumed that meant..."

"Hang on a second," Jack said, fixing his gaze on Carter, "what do you mean, you've been dealing with a few things?"

Sam exchanged a significant glance with Sheppard before replying: "Well, sir, we've been receiving a few... anonymous phone calls over the past few days. And with the visit being delayed so often up until now, I guess we just... forgot."

"'Anonymous phone calls'?" Jack repeated.

"Unscheduled offworld activations," Ronon explained.

"Oh? And?"

"There is no 'and,'" McKay replied, sounding exasperated. Jack raised his eyebrows in disbelief.

"Really? No life-suckin' aliens, no metal bugs masquerading as people...?"

"Not so much as a radio signal," McKay answered, sounding unimpressed at O'Neill's scepticism. "It's probably just an alien DHD malfunctioning, dialling its most recent addresses at random."

"Be assured, General," Teyla added, "as far as we can tell, there is no threat."

Jack raised a finger. "It's that 'as far as we can tell' business that worries me."

Sam shook her head. "We're monitoring the situation, sir. If anything changes we'll know about it."

"Yeah." Jack gave her a disbelieving smile and turned to address the room at large. "Now listen up, folks! I want you to know: I'm here on a tour the facility. I'll shake a few hands, take a few photos... I am not, I repeat, not here to save anyone, or solve anything, or shoot the bad guys. This is a courtesy visit to let everyone know we're all still rootin' for you back home. So don't go getting yourselves in trouble until at least twenty-four hours after I'm gone. Got that?"

Sam raised her eyebrows at him. "Don't you trust us, sir?"

"I trust you," he replied, pointedly. "Hey, Carter, can we get some food around here? The stuff they have on Midway is worse than airline food."

Sam smiled. "Yes, sir. Mess hall's this way."

McKay watched them go with a look of indignation on his face. "He trusts Sam and not us?"

"I believe the General was referring to his last experience on Atlantis," Teyla said, to which Ronon replied, "We saved him as much as he saved us."

"Yeah, well, just be thankful it isn't some suit from the IOA," Sheppard told them. "And remember – if the base does get into trouble this time round, we solve the problem. Speaking of which, there's something I need to talk to you about."

End of Part 1.