A/N: Before you read this, listen to the song "Defying Gravity" if you've never heard it. Preferably, listen to the version from Glee, since that's the one I've had stuck in my head for the past week and a half. Directly from a conversation between myself and lizook:

Me: Okay so I've had this damn song stuck in my head for days, a whole week, even. I've been singing it everywhere. In the car, at the bus stop, at work, at the doctor's office. I've been caught more than once, but it just won't get out of my head. So I'm writing [this fic] in hopes that by writing about having a song stuck in my head, it will alleviate the condition.

Liz: LMAO! That's... either brilliant, or way too hopeful.

We shall see. :) Enjoy, and let me know what you think!

It starts out as a hum. Not even a full-blown tune, just a jingle, just a snippet of verse here and there. It comes unexpectedly, in traffic or in the shower, or, God forbid, in the lab. It comes when you're holding a rib bone in your hand, examining the fracture patterns that radiate out from a bullet hole like spider webbing, when suddenly…

"Bones, are you singing?" Booth asked, incredulous. Brennan snapped out of whatever zone she had temporarily lapsed into and looked up at her partner, brows furrowed.

"What?" she asked.

"You, you were singing," he said, an uncontrollable smile creeping across his cheeks. "What's stuck in your head?"

"Nothing," she said, brushing off the accusation almost haughtily. "And I was not singing."

"Alright, humming, whatever. Oh, come on," he said as she picked up another rib bone, pointedly refusing to meet his gaze. "There's nothing to be ashamed of, it's just an earworm."

"A what?" she asked, glancing up at his face briefly.

"You know, an earworm," he explained. "A song that gets stuck in your head, it worms its way in through your ear—hence, earworm. You hear it and you can't get it out, so you just keep singing it until eventually something else gets stuck in your head instead."

"That doesn't happen to me," she said plainly.

"It happens to everyone," was his undaunted response. "You were humming, I heard you humming. I caught you, fair and square."

"I don't even know what fair and square means, Booth," she said tartly. "Now please, if you don't mind, there are human remains that require my full attention. Enough small-talk." Booth made an indistinct grumbling noise but quieted, crossing his arms over his broad chest and sulking around the edge of the table while Brennan eyeballed the inside of the victim's cranium.

But secretly, she knew he was right. This song—this undeniably charming song she had heard one of her nieces singing over the weekend—had clearly wormed its way into her head and was stuck there. She had been singing it to herself for days now, and with no respite. It would not leave the fringe of her consciousness. Everything she did, everywhere she went, it was as if she had theme music playing in the background. In the shower, stuck in traffic, even examining skeletal remains at work, it would crop up out of the ether that is the human subconscious and she would find herself struck with the overwhelming urge to start singing. It was completely inappropriate and making her work life very difficult, as she could only imagine the look on Booth's face if he were to hear her not just hum but actually sing in the middle of the lab. It would be totally unprofessional, not to mention absolutely mortifying.

And yet… she couldn't deny how satisfying it would be to wail out a tune right in this moment. The song felt like it was literally bouncing around the inside of her skull, and as improbable as that was, she couldn't deny the accuracy of the description. It was quickly expanding, growing larger and larger, asking—no, begging—to be freed. It wanted to be sung. It had to be sung. The quality of her work depended on it; if she couldn't sing to get this song out of her head, how could she focus on the remains in front of her?

That was, in the end, her defense. She had to sing as a process by which to temporarily relieve the cacophony of lyrics banging around in her head, so that she could focus on her very important work. Science was at stake, here.

"I'll be right back," she said, excusing herself from the catwalk and heading to the elevator. Bathrooms, she knew, were cavernous and echoed all the way down the hall. More than once she had heard Angela belting a rendition of "Alone" by Heart in the Medico-Legal lab's bathroom, only to be caught red in the face when she walked out and was met by a room full of smirking co-workers. No, she wouldn't go to the bathroom. She would find somewhere much more… sealed.

"What floor?" the suit in the elevator asked without really looking up at her. She saw that he had the 5th floor selected already.

"All the way up," she said confidently. She knew the upper floors of the Jeffersonian were primarily storage; the odds of someone needing a ride from one of those floors were slim at best. The man pressed the topmost button and they rode up together quietly for the next two floors. He stared resolutely at his reflection in the metal door, she at the confetti-patterned linoleum underfoot. On the third floor they picked up another passenger, also taking it to the fifth floor.

Perfect, she thought as they rode the next two floors in awkward silence, Brennan practically tapping her toes in anxiousness. In just another minute they'll get off on the fifth floor and I'll be… Before she could finish the thought, the elevator doors opened, releasing the two passengers.

Just as the doors were closing, Brennan was chagrined to hear a small, bubbly voice shout out, "Hold the door!" She was tempted to ignore them, or better, hit the 'Close Door' button and secure her solitude, but social propriety defeated her desire to be alone and Brennan stuck her hand across the threshold, allowing a woman quite as small as her voice to slip into the elevator with her.

"Thanks!" the woman chirped, taking a moment to look at the buttons before her smile widened. "Oh good, we're going to the same place." Brennan resisted the impulse to grimace. Of course this woman would take the elevator all the way to the topmost floor, right now, in this moment, when all Brennan wanted was thirty seconds of privacy. Of course she would.

"You know, taking the stairs is quite good for you," Brennan observed as they passed the seventh floor, continuing upward. The woman nodded, looking slightly confused.

"Uhm, yes, it is," she agreed.

"It improves your cardiovascular health, not to mention strengthens your leg muscles," she continued. The woman now looked positively puzzled, her large eyes squinting in an almost drawn-on frown.

"Alright," she said hesitantly. Brennan pursed her lips together—this woman was clearly not understanding her at all.

"What I mean is, maybe you should take the stairs the rest of the way up," Brennan said bluntly. If she could only get this woman out of the elevator already… "It would be good for your aging joints, anyway, the exercise." Now the woman looked positively affronted.

"Excuse me, my joints are not aging," she spat, all of her prior pleasantness having melted away rather quickly.

"Yes, they are," Brennan said plainly. "As are mine. We're growing older by the second."

"What is wrong with you?" the woman asked.

"Nothing?" Brennan responded quizzically.

"Never mind, you know, I will take the stairs next time," the woman huffed as the elevator doors finally opened, letting her out onto the topmost floor of the Jeffersonian. Perturbed but grateful to finally be alone, Brennan could barely wait for the doors to close before she took a deep breath and…

"I'm through accepting limits, 'cause someone says they're so, some things I cannot change, but 'til I try I'll never know…" There were no words to describe the sense of catharsis that came with practically yelling the lyrics to a song that had been stuck in her head for so long, but it was something akin to the feeling one gets after standing in line in the ladies' room after a movie with approximately 17 other female cinema patrons, waiting anxiously with your legs crossed until a stall with your name on it opens up.

"Too long I've been afraid of losing love I guess I've lost…" Brennan closed her eyes and let her admittedly off-key voice fill the empty elevator, reverberating off the walls and enveloping her. She held the air mic in her hand, singing into its invisible speaker—she could see a crowd of thousands clambering at the stage to get just one inch closer to her, just to say, "I touched the stage where Temperance Brennan brought down the house with 'Defying Gravity'."

"Well if that's love, it comes at much too high a coooooost…" Her arms reached out and embraced the lyrics, eyes closed, completely undone by the song escaping her. And it was in that moment, that exact, perfect moment, the apex of her performance, that the elevator doors opened up again on the first floor. Her eyes snapped open, and she felt the color rise to her face in a flash when she saw his grin on the other side of the door, caught between shock and amusement.

"I was wondering where you'd gone," he said slowly, face threatening to be torn in half by the unrepressed grin that stole his features. "Now I guess I know!"

"I… well…" she stumbled, having no idea how to explain herself to him. But before she could even try, he stepped into the elevator with her, pressing the highest button and sticking his hands into his pockets. He rocked onto his heels and turned to her, still smiling.

"So, you know the chorus to Sweet Caroline?"