She'd coughed so hard she'd had to stop twice. So hard she'd had to lean against a tree once, and the niggling feeling in Jack's gut had been growing by the minute. They were already over an hour from the Gate, and he'd been trying to ignore the voice that told him to turn around – it was just a cough, after all – but this one…. This one was just too long and too hard to ignore. Water hadn't stopped it. A cough drop hadn't stopped it – in fact, she'd hacked so hard she'd gasped for air and choked on it before coughing it out.
It ended with Carter cross-legged on the ground, her elbows on her knees and her forehead resting on her folded hands as she tried to catch her breath. "Here," Daniel offered, unwrapping another cough drop and handing it to her. One hand moved to pop it into her mouth before she returned to her curled-over state, desperately sucking in the menthol.
She was well aware that all three of her teammates were staring down at her in uncomfortable silence, and as soon as she could manage it, she told the ground, "I'm sorry."
"It's not your fault," Daniel soothed.
No, it wasn't, but that didn't really change anything. Rubbing a hand across the back of his neck, Jack decided, "All right. We're done. We're heading back."
She shook her head. "I'll be okay in a minute."
"Carter," he pressed, exasperated, "no, you won't. We've got another hour to walk."
And two hours round-trip. He was right; that sounded like torture, but to have the mission called because she couldn't hack it…. "You guys can go ahead and meet me on the way back."
Taking a knee in front of her, Jack tugged her chin up to look at him, needing the truth to really assess the situation but trying to keep his voice gentle. "Is it the walking, or is it the air?"
She sighed. "The walking's not helping. But I really think it's just dry."
"It doesn't matter what's wrong with it," he drawled. "If just breathing is making you worse, then we need to get you somewhere else."
Her eyes slipped shut in failure. "Sorry."
"Not your fault. Can you stand?" At her nod, Teal'c and Daniel carefully helped her to her feet. Jack stood, too, and snagged her pack from the dirt. "Let's go."