A/N - First time writing fic of any kind so your reviews, constructive criticisms and help will be greatly appreciated.

Rated T - Any innuendo here is not entirely unintentional...

Disclaimer: Bones is clearly not mine.

"Ah! Careful, Booth!" Temperance Brennan exclaimed as a sudden pain shot through her body.

"Sorry," replied Agent Seeley Booth, somewhat out of breath, "It's just kind of tight down here."

"Just keep going..." she said, anxious to continue, "I'm almost there."

"At least one of us is," Booth muttered under his breath.

"I heard that," Brennan said, annoyance in her voice.

Booth debated whether to just keep his mouth shut or to start yet another of their infamous arguments.

"You were supposed to hear that," he snapped back, after what was clearly a very one-sided debate. "Remind me again why you get to go first?"

Suppressing a groan of frustration, she craned her neck to face him. "We've been through this already, Booth. But to remind you, I know what I'm looking for and you don't. Besides," she said with a smirk, "you always go first."

He opened his mouth to protest, but soon decided against it. He really didn't have any idea what he was looking for.

Seeing Booth's silent surrender, Temperance smirked again and continued to crawl forwards through the cold and cramped tunnel.

Booth sighed as he saw the forensic anthropologist was on the move again. He had pictured himself alone with his partner in many dark, intimate situations but this one was definitely not on his list. Reluctantly, he hoisted himself up onto his elbows and followed her down the tunnel, trying not to land his arms on her ankles again.

It was all the spelunkers' fault, Booth had decided, after smacking his helmet against the uneven ceiling for the tenth time in as many minutes. If they hadn't decided to "investigate" the new caves opened by the heavy rains, then they wouldn't have found the bones. If they hadn't found the bones, he would never have been assigned to investigate a suspicious death on state land. If he hadn't been given the case, Bones wouldn't have been involved either. If Bones hadn't gotten involved, then she wouldn't have insisted that they retrieve the bones from the tunnels instead of digging in from above. And if she hadn't insisted on doing this her way, he wouldn't have been down here, banging his head, instead of out on the town, banging... He sighed again in annoyance. Damn spelunkers.

He was so lost in thought he didn't even realise that Brennan had stopped moving forward, until his elbow landed hard on her ankle once again.

"Sorry, Bones," he said quickly, hoping to avoid a repeat of their previous argument.

He was met with silence.

"Bones?"

Silence

"Look, Bones, I'm sorry, okay? But you should at least give me some warning before you just stop like that, you know? Hand signals, or brake lights, or, hell, even just "Stop"..." He trailed off as Brennan turned round in the tunnel, her eyes bright with excitement and her fingers holding what looked like a small pebble.

"I found a hamate!" she proclaimed, triumphantly.

Booth sank down to the ground in relief, "Thank God."

Temperance looked up at him, suddenly puzzled, "You know what a hamate is?"

Booth met her eyes. "It's a bone, right?" he said, confidently.

"Yes, but how did you- I mean, you usually don't understand-"

"Relax, Bones. I knew there was only one thing down here that could get you so excited," he said, flashing her a smile.

Brennan flushed slightly at his comment and Booth suddenly realised what he had said. "Uh, the bones, bones are what excite you, and I could tell, uh, by your voice and uh, yeah..."

She gave him a reassuring smile and simply asked, "Could you hand me an evidence bag for this?"

Booth immediately relaxed and passed an evidence bag to her waiting hand, silently thanking her for ignoring his earlier comment. He suddenly brightened as a thought struck him, "So you found a bone; that's good news, right? I mean, you got one, the others will be nearby, so we can just bag them up and head back soon, yeah?"

Brennan looked at him, cheerfully.

"Yep, we got one," she said, turning back around to scan the tunnel ahead of her, "only 205 more to go."

She could almost hear Booth's face fall behind her.

Like I said, first timer, please help me improve! Have got the rest of the story sort of planned out and more stuff will happen, I promise!