Author's note: Obviously, spoilers for Change in the Game. This is my take on the before, during, and after of that episode. I know everyone and their brother is writing a version of this (yay! something to tide us over until September!) and this is my take.

Cause & Effect

Temperance Brennan does not believe in accidents.

For every effect, there is a cause.

But when a second pink line appears on the pregnancy test she holds between her fingers, she forgets that logic.

Brennan considered, albeit fleetingly, that things would change when Booth's fingers whispered across the bare skin of her stomach, when her lips found his, when they shared the same serrated breaths in the darkness of his bedroom, and when they finally came together in a way that could only be considered breaking the laws of physics.

What she did not consider was how much things would stay the same. They are still friends. They are still partners. They still catch the bad guys and toast to each other with a drink after the day is done. The glances they share are longer, slyer. The stolen touches become more frequent, more meaningful. They spark something differently now - not an anxious unknowing of what lies beyond, but the deep knowledge of what does.

And that is something great big and amazing.

But they do not talk of that night. It is something sacred between them - something too big for words to properly describe. They think of it often in their own thoughts, but it not something to be revisited between them.

Nothing changes until everything does.

Two little pink lines only confirm what Brennan has already deduced. The nausea, the soreness, the exhaustion was enough evidence to come to a logical conclusion.

She is pregnant.

Even still, the confirmation sends her reeling. Knocks the breath straight from her lungs and makes her knees buckle, sending her to the edge of the bathtub.

In the back of her mind, she registers the soft thud the pregnancy test makes it when it hits the tile floor beneath her feet. She's too consumed with trying to wrap her own brand of logic around this situation.

It should be easy.

Cause: unprotected sexual intercourse with Booth four weeks ago.

Effect: pregnancy.

It's easy science. Cut and dry.

It's not something that could technically be classified as an accident (there is an absolute cause and effect) but it does not fit neatly into her plan, into her life.

There is an anxiousness that shakes her - a fear she can't name. There is a dread that sits heavily on her heart. There are a million thoughts rushing through her mind - they revolve mostly around the words 'baby,' 'pregnant,' and 'Booth.'

But in all of that - absolutely all of it - there is something bubbling up inside of her that feels a lot like joy. It's not exactly the happiness she is accustomed to feeling, it's something more. Something greater.

It is that foreign feeling that causes the corners of her mouth to draw upwards and her hand to rest on her still-flat stomach.

She lingers there, on the edge of the bathtub, hand on her stomach, over the life she has created, until Booth knocks on her door.

She tucks this secret of hers away. Leaves it right there in the trashcan with the positive pregnancy so that she can concentrate on the murder investigation and Angela's baby and being impossibly close to Booth all day.

It is not as easily as forgotten as she would have liked. It's right there with her - literally and figuratively - as she moves through the day, Booth at her side.

And then she meets baby Michael and her world tips completely off its axis.

A baby. A real, live little human being.

Any doubt she had of keeping the baby quickly disappears when she sees his chubby cheeks and sleepy eyes. He is perfect.

Sneaking into see Angela - exhausted, but radiating happiness, gives her a peak into what she can expect in nine months time. Though she doesn't fully believe Angela's description of childbirth, she is oddly anxious for her time to come.

She is still hesitant. She is still scared. But, there's a part of her that is excited, too.

When Booth volunteers to walk her home, her heart hammers in her chest at the thought of being alone with him. Her fingers itch to touch him all while she wars with herself over telling him the news or keeping it her own secret for a little while longer.

But when he gushes about the happiness a baby brings and when he asks her "What?" she can't help herself.

She tells him the only way she knows how: quickly and honestly.

In the seconds following this truth, she worries if it was the right thing to do, if he'll be happy or upset with her, if they'll be able to make this work.

And then he laughs. It's happy and soulful and it hits her right in the heart. She can't help but do the same.

But when the laughter flutters away, into the late-night spring air, they are left there on the sidewalk in silence, this great big thing between them.

"Say something," she prods anxiously, switching her weight nervously from one foot to the other.

"I'm…" He struggles for the words. He's in shock, but he's still over the moon excited at the thought of having a baby with this woman before him. But when he looks at her face, reluctant and scared, he chooses his words carefully. "How are you?"

"Tired. Nauseous; morning sickness hasn't fully hit yet, I imagine in a few more weeks it will be a more prominent side effect of the pregnancy."

"No, I mean… emotionally. How are you feeling about this?" he presses.

She tucks a loose strand of hair behind her ear and considers his question before answering. "I find that I am unsure of how I feel about having a child. On one hand, this was not planned. And we are not a couple like Angela and Hodgins. But, on the other hand…"

"Yes, Yes?"

"I am surprisingly anxious about the possibility of a child that shares my DNA and your DNA. I don't know if I have ever felt this emotion before, so it is hard for me to explain what it is I am feeling."

"Happy?"

"No. I know what happiness feels like. It's more like…" Her hand unconsciously floats over her stomach and she glances down, averting her eyes from Booth's and whispers, "it's more like love."

Booth smiles goofily at her, his eyes fixed on her stomach, right where her hand is.

"I do not think I have had enough time to properly process my emotions," she states matter-of-factly, dropping her hand.

"How long have you known?" he asks, pulling his eyes back to hers.

"I just found out this morning. I wasn't sure the best time to tell you. Is this too late? Too soon? I am having a hard time with the conventional ways in which people deal with an unexpected pregnancy, even though we have just gone through this with Angela and Hodgins. They are very different from us."

"I'm glad you told me when you did, Bones. Perfect timing."

"How do you feel about this? You know that I would never ask you for any kind of assistance. I have plenty of money to care for a child."

"I'm a little… surprised. But, god, Bones. A baby? We're having a baby! I could kiss you right now!"

"Okay… okay."

"Okay?"

She nods.

He steps towards her until they're sharing the same space. Brennan can't help but swallow the lump in her throat at his nearness. And when his fingers push through her hair, his thumb resting on her cheek, her eyes flick from his eyes to his lips and back again.

Booth draws her into him and finally their lips are meeting. The same spark shoots through them. Just like the very first time they kissed and just like the last. The passion and fire still exists, ever unchanging, and the give and take between them in this kiss is proof positive of that.

When he has kissed her good and long and hard, he pulls back, catching his breath, resting his forehead against hers.

"A baby," he whispers, awed. "We're going to have a baby."

Brennan is ready to cry. She feels the hot tears stinging her eyes and the closing of her throat as she tries to push them down. She wants to blame it on the excess of hormones coursing through her body, but she feels as thought that would be a lie. She feels… overcome. It's an odd sensation, but there doesn't seem to be a more apt word to describe this moment in time. Booth and her and the possibility of a baby - their baby - right there within her.

"Can I just…" Booth's hovers over her stomach, waiting for permission to touch her in this way. It's an intimate gesture, one he's certain that Brennan will be uncomfortable with.

"You wont be able to feel anything," she tells him. "The fetus is not even an eighth of an inch big yet."

"No, I know. I just…" He presses his hand to her stomach and laughs again in the same deep down, happy way he did when she first told him the news. "A baby, Bones. Our baby."

"You keep saying baby," she says, scrunching up her nose.

"Because I still can't believe this."

"It's not so hard to believe, I suppose. A natural consequence of when two people have unprotected sexual intercourse. If you'd like further proof, I could show you the pregnancy test. Or schedule a doctor's appointment or…" He looks up at her and grins. "Oh… I understand. It is very unbelievable that we're having a child together."

"It's all so crazy and wonderful and terrifying and wow."

He finally lowers his hand and shakes his head, still trying to wrap his mind around the thought of having a baby with Brennan. When he looks up at her, he sees the tears pooling in her eyes and the look she gets when she is uncertain of something (not a very frequent occurrence) and wants to run.

"Hey," he soothes, stroking his thumb over her cheekbone. "What is it?"

"I understand cause and effect. For every effect, there is a cause. This is the effect of a cause - of us sleeping together. I do not believe in accidents. I do not believe this baby was an accident. But I am having a very hard time comprehending the way our lives are going to be changed by something so… unplanned. I find I do not know how to prepare for this."

"I don't think you can, Bones. This is something science can't really prepare you for."

"Anthropologically speaking…"

"No. You can cite all of the research and read all of the books, but nothing is going to prepare you for the moment they put this baby into your arms. Nothing."

"Do you think that I'll be a good mother?"

He smiles, broadly and freely. "The best. Bones, the best."

"And we'll make this work? You and me and the baby?"

"It's all going to work out. I promise."

"I would argue your point - that you do not know what the future will hold or how this will work out - but you have left me with enough evidence over the past seven years to believe that you always keep the promises that you make."

"Always," he grins. "Come on. We can stay at my place tonight."

He extends his hand to her and when she takes it, they interlace their fingers together. They change directions easily, hand-in-hand, and continue on their way.