There were deer on this planet. Well, something like deer. They were smaller, slighter, with legs that faded from brown to nearly black near the hoof. They didn't seem to be afraid of SG-1, lunching silently near the treeline a hundred yards from the ruins, and Jack wondered how long it had been since the place had seen a human.

And then he wondered if he was thinking about it all wrong, and they were missing something, and the place saw humans all the time. He scanned their surroundings again.

And spotted Captain Carter twenty feet away, leaning heavily against one of the low stone walls. She hinged at the hips, her lower back overly arched, her eyes closed.

And her face read sheer pain.

The second she heard footsteps, she straightened – mostly – but the damage was done. "A little sore, my ass," he accused, irritated. "What's going on?"

Her cringe probably wasn't because of him. "Sorry, sir."

"Don't be sorry. Tell me what's wrong with you, Captain." If she was sick or injured or generally unfit to be in the field, he needed to know that – and pronto.

"I just... I slept through a dose of ibuprofen last night. I usually try to stay ahead of it, and it's fine, but-"

"Ahead of what?"

The cringe worsened as she scratched uncomfortably at her scalp. "Uh... Girl stuff, sir."

He blinked. And then, like the enlightened, formerly married, completely comfortable with women's issues man he was, he croaked, "Oh."

Turning her face away, she muttered again, "Sorry, sir."

Well, didn't he feel like an ass? "Is it always this bad?"

She huffed. "No. Not for years. It actually used to be much worse. I'm okay, really. And if we were walking or running from bad guys or... doing anything, honestly, it probably wouldn't bother me so much. But just standing here... I've been doing theorems in my head to distract myself, but it's not really working."

"All right. I can handle watch," he offered. There was nobody around, anyway. "Why don't you, uh..." Stare aimlessly at the animals like he'd been doing?

"I'm actually kind of interested in these rocks, sir. They have some characteristics that are pretty rare on Earth."

"Take rock samples!" he finished. "You have the stuff for that, right?"

With a smile, she said, "I'll make do."