Jack O'Neill really didn't like enclosed spaces.

It had gotten worse after his time in Iraq, but they hadn't ever really been kosher, when he actually stopped to think about it. The only tight space he actually enjoyed was a cockpit, though that was only because the rumble of a jet fighter's engines firing up, and the rush of screaming into the wild blue yonder gave him more freedom than anything on solid ground ever could.

But all cockpits aside, he hated small spaces. Especially small spaces trapped immobile beneath a mile of rock.

Which was why he was pacing the length of a stationary subway train, instead of waiting patiently like all the other passengers. It was currently lying dormant halfway through an underground passage. They'd already been stuck for two hours, and the unfortunate positioning of the tracks prevented secondary transport from moving the passengers. They'd been told to sit back, relax, and wait for repairs to occur.

Needless to say, Colonel Jack O'Neill was not a happy camper.

He'd finally succumbed to his fraying nerves, and pulled his rank out of his back pocket to get special permission to travel between cars. And so far, that seemed to help a little bit. He could breathe, at least, which he couldn't do trapped in a single compartment.

So he walked, slowly, carefully, along the shadowed length of the train. The primary lights had been doused, possibly because of power failure, possibly because of passenger complaint, and most of the passengers he passed were sleeping. He spied some who were reading, and some who were speaking softly to one another, bonding over their mutual misery.

He ignored these. In fact, he ignored most of them, and only glanced at any of them to create a distraction for himself, as something to think about other than the fact he was trapped in a tin can a mile underground.

He was making his way through his fifth car when he nearly tripped over a passenger lying sprawled in the aisle. The snores issuing from the man assured Jack he wasn't dead or injured, and so he simply sidestepped to sidle his way past the obstruction. But as he turned, his eyes caught sight of a passenger sleeping against the wall seats besides the nearest hatch.

Even in the darkened car, he could see the blonde hair, the long legs, and soft cheek of a woman he'd thought he left in the Arctic. She was in civvies, blue jeans and a trim sweater, barely discernable under the coat she was utilizing as a blanket, and her eyes were closed behind the delicate frames perched on her nose. But he still recognized her, and he still felt the unexpected jolt in the pit of his stomach at the familiarity.

It wasn't the familiarity she and her friends had claimed—he didn't know them, and he didn't know her. But everyone in the country knew her face, and even now, it was like staring at the newspaper, her smile gracing the front page for months in the wake of first her promotion and assignment to the mission, and then in her death.

The country had mourned the loss of Mission Commander Carter, who had single-handedly reintroduced the world to the wonders of NASA. It was under her expertise that the dying agency had been revived and rejuvenated, and the world had lauded her for it. But she was dead now, and this woman who wore her face shouldn't be here.

Jack had heard rumors that she and the other two had been put into witness protection, separated and silenced. He knew the reasoning behind it, and he approved of it. He liked his world, and he wanted to keep it. He didn't want any of them in any position to be able to reinstate their own time line, if what they said was even true in the first place.

They were supposed to be kept away from anything that would tempt them, including their respective careers and fields of expertise, prior acquaintances, friends, and family.

So what in the hell was she doing here?

Chicago was his town. The Air Force knew he spent all his off-mission time here. It was where he had grown up, and it was where he had raised his son. It was where his ex-wife had chosen to stay, and it was where Charlie was going to college. It was on every record imaginable, so why, why was this woman on a train bound for his city?

Had she come to seek him out? Had she somehow figured out where he lived, and come to try once more to convince him of her story? He wouldn't put it past her, or either of her compatriots. They were all wild cards, and extremely dangerous ones at that.

Before he could ponder it further, the woman stirred, and a moment later blue eyes blearily blinked their way open. They caught sight of him first, and those eyes focused on him before she so much as glanced at her surroundings. And when her lips spread into an easy, welcoming grin, Jack realized she didn't care where she was.

She had eyes only for him, and the intensity of her warm, blue gaze sent tingles racing up his spine.

"Sir…"

The whisper was soft, inquisitive, but inexplicably happy. And in that moment Jack realized that this Samantha Carter recognized him as well—but she was recognizing him as someone else entirely. In that second in time, she was seeing her Jack O'Neill, and whoever she knew him to be… she loved him.

"Ma'am." Jack's one-word deadpan was all it took to shatter the woman's vision of him. She blinked, and her gaze turned razor-sharp as she searched first him, and then the train around him, for discrepancies. And apparently, she found them, and her eyes darkened at the sudden reality.

She straightened from her slumped position against the partition, running a hand over her suddenly haggard features. The coat slid from her shoulder, and Jack watched its descent over soft curves until it pooled to a rest in her lap.

Blue eyes flashed up at him one last time, but they had lost their warmth.

"O'Neill." Her amended greeting was dull, and decidedly less respectful than her first had been.

It grated, and the officer in him bristled.

"That would be Colonel O'Neill, Miss…" He left the salutation hanging, so she could fill in the blanks of her new identity. She wouldn't be Samantha Carter anymore.

But instead of receiving clarification, an icy glare was sent his way. She leaned towards him, intensity bleeding from her in waves.

Jack swallowed.

"That would be Colonel to you too, O'Neill," came the fierce counter. Blue eyes glittered icily at him. "I have been serving since the day I turned seventeen, and I've spent the past fifteen years facing things you can't even imagine. Don't even think about trying to pull rank on me."

Jack blinked.

He'd forgotten she was military—if she and her friends were telling the truth. And on the verge of a dress down from the woman, he was currently willing to accept that part of their story. Some things you just can't fake.

After a long moment, Jack nodded mutely in acceptance. Almost without thought, he maneuvered himself into the seat adjacent to hers. Her eyes followed him, but she didn't say a word. Once settled, he gazed at her, and she met his stare squarely and without hesitation.

"Let's start over," he began as conversationally as he could. He extended his hand towards her. "Jack O'Neill. Nice to meet yah."

She stared at his hand for a long moment, but eventually grasped it with a strong, firm grip. "Nice to meet you," she returned.

Jack could almost see a smile in her eyes, but a moment later her gaze shuttered once more. And it didn't slip his notice that she didn't offer a name in return.

"So… what're you known as these days?" He figured the straightest inquiries would get the straightest answers. And when she rocked back in her seat, he knew he was right.

"Blaine. Jennifer Blaine." The name rolled off her lips with impeccable ease, but her nose wrinkled in the slightest indication of disgust.

The name might have fit the picture—the dirty blonde hair and the teacher's glasses and everywoman attire—but it wasn't hers. No, her name belonged to a dead woman.

"Well," he said, "it's a pleasure, Ms. Blaine."

This earned him a hard stare. He let the silence linger a minute, before trying again.

"So what brings you to the city?"

He didn't even understand the reason why he was attempting to strike up a conversation with this woman. Just moments ago he had been outraged she was within city limits, and now… Well, now getting away from her was the last thing he wanted to do.

"I live here," she answered.

Jack raised his eyebrows at that. So the Air Force knew she was here. Go figure.

"Well, what do you know, so do I."

This time, a smirk did cross her lips. "North Side," she stated bluntly. "Next to Lincoln Park."

Jack blinked again. She shrugged.

"My handlers may have mentioned something in the brief."

"They told you where I live?"

"Not exactly."

"But you've known all this time."

Her blonde head nodded, throwing him for a loop. Somehow, he wasn't surprised. The federal government was well-known for making less than great decisions. But what did surprise him was that she hadn't sought him out. He hadn't found her lurking outside his home, or running into him at the store, trying to get a moment alone with him.

He couldn't say that he would've been able to do the same, in her position. To her, he was her best shot at getting the government to reassess their circumstances, and the policy to not do anything to correct the timeline. But she had left him alone.

Why?

His gaze wandered as he considered the situation, and saw that they had drawn some attention. Well, not they, exactly.

She had drawn some attention.

A passenger off to the right was casting furtive looks towards Jennifer Blaine, repeatedly looking for some sort of confirmation that the woman was who she appeared to be. Glancing back at his companion, Jack realized that he wasn't the only one who had noticed.

"Someone you know?"

Keeping her eyes trained on her hands, twisting subtly in her lap, Ms. Blaine shook her head. For a moment, Jack considered making a crack at the bizarre situation, but seeing her discomfort stayed his tongue. So instead, he merely glared at the inquisitive passenger until the woman noticed and returned her attention to her book, properly chastised.

"Well," he remarked, his tone forcibly light and nonchalant, "I guess this wasn't the right day to take the subway after all." His companion glanced up at him once more, almost appreciative of the distraction. "I figured since the weather was starting to get bad, taking the train would be safer than driving. Too bad the forecast didn't mention overcrowding with a chance of technical malfunction."

"I could probably fix it," she replied softly.

Jack arched a brow. "Really?"

She nodded. "My Ph.D. was theoretical astrophysics, but my undergrad was a dual degree in physics and electrical engineering. It probably wouldn't be too difficult to figure out."

"Well, in that case," Jack scoffed, "why don't you?"

Her eyes narrowed, until she was pegging him with a sharp, skeptical glare. "Because if I did I would be remanded into federal custody, my fake name would be stripped away, and I'd most likely spend the rest of my unnatural life in the bottom of the deepest pit the government can find."

"What?"

"It'd be a breach of contract. My freedom is contingent upon the condition that I completely divorce myself from everything that defined me as a person in my old life—my real life. That means no Air Force, no astronomy, no physics, no electrical engineering. I'm also prohibited from interacting with Mission Commander Carter's sphere of influence, which essentially precludes any form of academia."

Jack let the full weight of her words sink in. He'd figured there would be restrictions on what she would have access to— the obvious being her friends, and any attempt to make contact with anyone she claimed to know besides them. But hearing all of it from her own lips… it was clear how difficult it was.

Jack knew that, if in her shoes, he would have had some major difficulty.

But even so, her friend's words echoed in his mind, claims that his son, his Charlie, was dead. Shot with his off-duty weapon.

And just like that, his earlier sentiments were renewed. Anything that kept this world safe was necessary. Even if this one woman suffered for it, so be it.

Charlie came first. Always.

"Well it sounds like you must be pretty bored then," he commented drily. "Gives you time to think, if you're into that sort of thing."

His attempt to earn a smile fell flat, when her eyes darkened and her gaze lowered. There was a furrow in her brow he could not quite interpret—he couldn't tell if she was angry, sad, or something else entirely.

"Look, Ms. Blaine—"

"Don't call me that."

Her words were sharp and biting, and quick enough to take Jack by surprise. But he understood, in a way. It wasn't her name, and for him to look so similar to whom she knew in her world… But even so, he couldn't exactly call her Samantha Carter, now could he?

She must have sensed his quandary, because a moment later she was speaking once more. "At least call me Jennifer, or something," she muttered. "Ms. Blaine makes me sound so… old."

It wasn't her first choice of descriptors, he could tell, but he let her have it. He nodded. "All right. Jennifer. Jen. Jenny." He wrinkled his nose. "Jennifer?"

She nodded in acceptance, and he agreed. "Jennifer it is."

"Why even bother?" she asked him bluntly. "You're not going to see me again once this train makes it to the station. Not much point in deciding on a nickname."

Realization hit him like a kick to the stomach. She was right. Why was he trying to get familiar with her? She was either certifiably insane, or she wanted to bring about a world where his son was dead. Either way, she was bad news, and yet… He couldn't help himself. That much had already been determined; the past few minutes had shown that much.

This woman, regardless of who she was or who she wasn't, had a certain magnetism about her, and he hadn't even realized she was pulling him in.

Had Mission Commander Carter been so alluring?

He couldn't help but wonder.

In the end, he hid his sudden apprehension with a shrug. "I was raised polite."

Jennifer Blaine snorted in derision. "Yeah, I bet."

The righteous indignation that bubbled up within him was cut short at the sudden tremor that jostled the train and its occupants, eliciting cries of concern until the lights flickered on and the train began to slide forward. Cheers filled the car, and a disembodied voice informed them that they would be reaching their intended destination within the next half hour.

Jack gave a sigh of relief, then looked to his companion. The warmth he had begun to see in her eyes was gone, leaving behind a cool disinterest. Disappointment filled him for a brief moment before he shook it off.

"Well," he uttered gamely, "that's that."

Her lips pressed into a thin line, and a tired hand tucked a stray lock of hair behind her ear. Her eyes refused to meet his.

"That's that," she echoed softly.