A/N: Warning for one instance of blasphemy. If that offends you, don't read this.

Stargate Command is never silent, but there are hours of the day when its ambiance settles to a latent buzz; when footsteps in the corridors drop to nothing but an occasional, distant susurration against concrete, when the only chatter is in the background whirr and mutter of the machines that make living and working this far underground possible. These tend to be the hours when folk with normal lives are fast asleep, the innocuous stresses of their days working their way out via dreams that cannot hope to encompass the realities of the universe. Jack O'Neill often wonders whether what the human race – at least the one largely confined to Earth – needs to settle their woes is a good old dose of perspective. He suspects that loving your neighbour for their petty transgressions might be a darn sight easier when set against the hostile bent of the guy two doors – or two stars – over.

He likes the SGC at rest. It's a reminder that whatever's going on elsewhere, peace – or a measure of it, at least – is still possible, even in the middle of an intergalactic war that is creeping closer by the day. Besides, most of his adult life has revolved around moving from one military base to another, tours of duty that offered no certainties other than that they would end with a new assignment in a different field. The irony is that, though he now travels further than he ever did when he was stationed in Iraq, or Okinawa, or Germany, he can do it right from his own backyard. It's glorious, he thinks, even if that backyard is lacking the one thing that Jack O'Neill would give up every trip across the universe for in a heartbeat to have back.

But dwelling on such impossibilities isn't healthy, and being in the SGC – at any time – is a big help towards never disappearing down the black hole he'd teetered on the edge of following Charlie's death. It doesn't mean that his own brain doesn't continue to do the processing-while-asleep thing, though. Which is why he's here, now, ambling easily into the quiet control room at 4.30am on a Tuesday morning, two hours before his shift is due to start.

Siler and Simmons are at the controls, and it doesn't take long for him to figure out that all is not well in the state of Colorado.

"No, that's not it either," says Siler, his forehead wrinkled in concentration beneath his glasses as he stares at a screen on which is scrolling gibberish strings of numbers.

"Maybe we need to go back one," Simmons suggests. "That last sequence, we could try inverting it."

"Trouble, gentlemen?" Jack asks, hands in his pockets. He takes one out to wave them both back down as they start to stand to attention.

"The dialling computer's gone haywire, Colonel," say Siler, frown still in place.

Jack raises an eyebrow. "Ah, technical terms. My favourite."

"It's not selecting the chevrons in sequence the way it's supposed to," Siler explains.

"You mean we keep dialling wrong numbers?"

Simmons nods. "Something like that, sir."

"How long have you two been trying to fix this?"

Siler quirks his mouth in an uncomfortable grimace before he says, "Going on four hours, Colonel."

Jack looks at his watch. SG-1 are due out to P4X-672 at 1000 hours, and there are at least three other teams rostered to move out before then. "Maybe it's time to call Major Carter in, see what she can make of it, huh?"

"Yes, sir."

He goes to the phone on the wall and dials the switchboard. When the operator answers he requests an external line to Carter's place. There's a slight pause before the voice on the other end of the line comes back again.

"Colonel, my records show that Major Carter is currently on base."

"She's here?"

"Yes, sir. Her ID hasn't passed through security since 0600 Sunday, sir."

"Right."

"You still want me to connect you to her home, sir?"

"No. Thank you."

He puts the receiver down thinking, For crying out loud, Carter, what will it take for you to get a life?

"Major Carter's on base," he tells the two men. "Dollars to donuts she's in her lab."

Simmons turns towards him. "Would you like me to go get her, sir?"

Jack eyes him: young, smooth-skinned and with a crush on Carter that must be visible from space. He'd ribbed her about it once – only gently, mind you, a little oblique reference that was only just touching the line. But he hasn't forgotten how much he liked the tiny pained blush she couldn't quite keep off her cheeks. So much, in fact, that he'd made a mental note never to risk seeing it again. "No, no. You keep at it. I'll go."

He leaves them to it, because even though he could just call her up via the base tannoy, he wants to see just what Carter's working on that's so important she hasn't gone home in two nights straight.

When he reached the lab he's so busy thinking of pithy comments about life outside Cheyenne Mountain and the necessity of decent sleep that for a moment he doesn't register just how quiet it is within. When he does, he looks around, thinking for a moment that perhaps, contrary to his expectations, she has actually found herself a duty bunk to get some shut-eye before her shift begins. It's only the second time his gaze sweeps over her desk, half obstructed from his view by various pieces of equipment and her computer terminal, that he realises Carter's slumped across it.

For a split second his heart freezes, and then the years of training kick in and he slides into automatic pilot. He takes two swift, sharp steps around the desk and is about to check her pulse when she moves slightly, murmurs something, and he realises that she's just asleep. Carter's crossed her arms on the desk, rested her cheek against them, and drifted off.

It's not the first time he's seen her asleep and given how they spend most of their time it won't be the last, so Jack doesn't really understand why this, here, now, effects him in quite the way it does. He doesn't pause to consider it, clamping down on that tiny inner earthquake so quickly that he can almost pretend he didn't feel it at all.

"Carter," he says, sliding his hands into his pockets. "Come on, Major, wakey, wakey."

She doesn't stir, and that surprises him, because he's seen her go from zero to 60 out in the field, up and out of her bedroll with her P90 at the ready before the last letter of her name has fully left his lips. Here, though, she's out for the count. He glances at her screen, wondering again what she's been working on that could burn her out so completely, but the SGC screensaver is bouncing slowly around the darkened background.

Jack grimaces to himself, looking around. He considers using one of the pens in the pot on the desk to poke her back to consciousness and decides against it. Another beat, a single breath and he leans forward, hands still in his pockets, to speak directly into her ear.

"Sam," he says, softly. "Time to wake up."

This time there's a reaction. She hums, a slow, happy little murmur that unexpectedly thrums a chord deep in his chest. He leans back, quickly, as Carter's lips curve into a lazy smile. She lifts her head, still smiling in a way he's never seen before and will from now on spend a lot of time trying to forget. She opens her eyes and looks at him fuzzily, slightly unfocussed, still smiling that smile and all Jack can think is Holy Mary Mother of God.

"Hey," she says, her voice low and throaty from sleep, running one hand through her hair. A second later her eyes snap open as wide as he's ever seen them, as if she's suddenly realised where she is. "Sir! Colonel!"

Jack clears his throat. "Just one of those will do, Carter."

"Yes, sir. Colonel." There's a flush rising from her chest, making its way up her neck to burnish her cheeks and it's not helping him, at all, because it's clear that she's pretty damn flustered right now and if he's not careful he's going to spend a lot of time wondering why.

"You're going to have a hell of a crick, Major," he tells her. "We do have actual bunks in this facility, you know."

She's not looking at him. "Um, yes sir, I was just… I was running some simulations on the rate of decay in the naquada reactor, and I guess I lost track of time."

Jack nods. "Well, you're needed in the gateroom. There's a situation. Siler and Simmons have been trying to sort it out, but they're not getting anywhere, and if it doesn't get resolved soon it's going to start effecting mission schedules."

"Right. Yes, sir. I'll – I'll be right there. Can you give me just a minute?"

"Sure. Don't be long."

"No, sir."

Jack nods and leaves her to it. At the door he tries not to look back, but fails. Carter's frozen in place, fingers against both cheeks, staring at her inactive screen, and not for the first time since he's known her, Jack both wishes he knew just what was going through her head and is intensely grateful that he doesn't know.

He turns away, his footsteps scuffing lightly against the concrete as he heads back to the gateroom. It's not so quiet here any more, he thinks. There's a sound he can hear, echoing over and over in his mind.

It's a sleepy little murmuring hum.

[TBC]