Existence of Differences

Spoilers: The Day We Died mainly but all seasons are for grabs.

Disclaimer: I only wish I owned Fringe, I don't!

There are things they don't talk about, some new and some forbidden because of certain issues that arise when said conversation are brought up. Olivia often found herself being stared at, wondering what he was thinking and why he was thinking that thought. No one knew the truth, no one but them…who would have believe them? Despite how much of a difference he had made in the lives of so many, only she remembered him…only she can call him hers.

Walter and Astrid and Broyles see a young MIT professor with a knack for the strange science but she sees Peter Bishop, her lost lover and best friend. She doesn't give a reason why but she begged Broyles to let him come on as a civilian consultant…of course her boss gives Peter a week trial run to see how he handles everything. He remembered everything as clearly as he ever had… the sight of her and her willing him to remember…poof he was her Peter after a week of talks and constant willing. He has got his science knack back, handling Walter is a breeze where others have tried and failed…often shoving their badge at Broyles in the process. Being a partner, they understand each other clearly…Broyles soon saw it all and agreed without a second thought.

At night, it's just him and her at her apartment, doing things they often did before. Watching a movie, making dinner, going on the occasional date…always ending the night in each other's arms even if sex is involved or not. They remember every moment up until the machine, Peter said he remembered more but doesn't say what, putting up the first of their five allowed non-disclosures. She respected it because she had one of her own…non-disclosure from him to talk about the other Olivia. They each have five more for a lifetime, discussing everything but those five things they don't want to talk about.

It was one night while curled up on the couch that the door to her apartment opened and they both looked up to see Rachel and Ella. Peter acted like he did with people he knew but now didn't know him and just smiled. Rachel shut the door and eight year old Ella hopped right over to Peter and Olivia, smiling.

"Hi, I'm Ella."

Peter smiled at his favorite lab assistant but she only knew him as a stranger now. "Hi, I'm Peter."

"Are you Aunt Liv's boyfriend…she doesn't like people hugging her and that is why I ask, because she lets you hug her."

Peter pulled Ella into his lap and held her like he remembered doing for so many years before she grew into a young woman and eventual Fringe Agent. However, that lifetime wouldn't be…not anymore. In the lifetime she had, she was innocent and had her parents. "I have a question for you, if you can answer it…I'll answer yours. Is that fair?"

"I guess, what's your question?"

He looked at her and smirked, "what's behind your ear?"

"Nothing, it's my ear…my hair maybe."

Peter pulled a coin from behind her ear and Ella gasped as he held it out to her, she then smiled at him. "I knew that was behind your ear, you didn't know though."

"Again, again!" She eyed him and Peter looked at her, smiling.

"No more, go play while Mom, Aunt Liv and I talk."

Ella groaned but headed off, immediately listening to him but ran back and whispered into his ear as she did. "I like you, thanks Peter." She hugged him and ran off towards the back rooms. Peter found himself on Rachel's approved list instantly…he only longed for Ella to remember him too.

Being back was hard at times, the looks he'd give Walter and wish he could say it had been done before but he couldn't Peter often just nodded before helping his father with the madness he wanted to perform. The Walter he knew wasn't there anymore…this Walter practically lived at the lab…working in the lab and living in the spare office. He even offered to share a house with Walter, so the man could be more independent but his father, who technically wasn't his father, called him perverted and told him to leave. Peter eventually came back to find the older man had forgotten it all.

"You there," everyone turned to Walter, "young man, get me the bone saw please."

Olivia walked over, "Walter…his name is Peter and he's trying to assist you, please make an effort to remember his name."

"I have no need to remember his name…for you it's different, he's your lover. He has no relationship to me so I only need him when he is useful."

"Walter…please make an effort…Peter doesn't have to be here."

The old man eyed her, "if he doesn't need to be…he can go, just get me the bone saw before you do and don't let the door hit your ass on the way out."

Olivia pinched her nose, she was very patient with Walter but his arrogance reminded her of the mad scientist she had removed from St. Claire's in another timeline. Peter stayed however, despite the no need to…Olivia understood why and it was to be closer to his father.

That's how they got into their first fight after Peter had been 'recovered' so to speak, she wanted Peter to tell Walter the truth…about who he really was. He argued that it wasn't right and would just cause more trauma…not to mention issues with the FBI and Fringe Division. She had said that Walter needed to know…to understand. She was tired of having to deal with his bullshit, she had before and she didn't want to again. Peter said she shouldn't have remembered him and then everything would have been fine…she wouldn't remember two lifetimes. He left in a rage and didn't return when she went to bed.

Olivia woke to the bed dipping and rolled over to see Peter laying down beside her, he reached out and touched her cheek. "I'm sorry, I didn't mean that…I'm just frustrated too."

She curled into him and Peter held her, "don't leave me…I'm tired of being alone."

"You'll never be alone again Sweetheart," he kissed her head, "I promise…never again."

Four years of everything passed and Peter made the decision to tell the truth the day their baby girl was born…he said Walter deserved his granddaughter. He said Elizabeth deserved her grandfather…the better of the two and one that could teach her everything she needed to know and more.

After telling Walter everything, to which the man began remembering…eventually calling him son, Peter laid Elizabeth in his arms.

"This is your granddaughter, Elizabeth Carla Bishop…we're calling her Elli for short."

Walter smiled and looked at Elli, "hello Elli…I'm your grandfather, Walter Bishop. You can call me Grandpa though…now your mother and father are…

Peter watched as he sat on Olivia's hospital bed as his family was once again whole, this time with a new addition that would help them all. Olivia joked that it had happened without the world imploding...although Peter found the joke morbidly true.

A/N: Just wrote this because I felt like it. A different way Season 4 could play out...

School is starting soon and I'm going to try to finish my new fic 'A Moment's Difference' before it does and start posting. At the moment it's 27 chapters and counting, we'll see how far it gets but I'm thinking between 35 and 45...but who knows.

It basically covers two timelines, one where Olivia made it to Peter before he went with Walternate and Newton in Northwest Passage and another lining up with 3x21, The Last Sam Weiss. It's going to be up and down and all around...possibly mind blowing. Oh...and the First People included...wait and find out.