O'Brien was at a loss to give her an explanation. All he knew was that he had been called into his boss's office a few hours before. He found Seeley Booth there and the boss informed him that he would be replacing Agent Booth as the Jeffersonian liaison. The three of them spent the next hour discussing logistics, and Agent Booth gave him an outline of how to work with Doctor Brennan. He could tell there was a wistfulness in the way he talked about her, and he seemed to feel that it was important that O'Brien understood the ways she processed information and communicated - to ease the transition for both of them. In the discussion, Booth never made light of Brennan's idiosyncrasies, but he felt it was important that O'Brien respect that her way of doing things, while unconventional, was tremendously valuable. O'Brien sensed a real tenderness when Booth talked about her and felt that he was being handed a precious gift and Booth wanted to make sure she was appreciated and cared for. Booth then got up and quickly left the office. O'Brien sensed emotion in his voice and body language, but he stayed to receive final instructions from the boss. On his way out to head to the Jeffersonian, he stopped by Booth's office to have a private chat with him because he sensed there was something underlying this decision that he wasn't being told. But Booth was nowhere to be found.
Brennan could see that O'Brien was at a loss for words, so she grabbed her cell phone and was about to hit Speed Dial 1 when she paused and decided against her first instinct. She scrolled through her contacts for "Hacker" and put the call through. "Andrew. This is Temperance Brennan. I'm fine. I have Agent O'Brien here in my office and he tells me that he is my new liaison with the FBI. Is that true?" O'Brien sat across from her hoping that her conversation with his boss would also give him answers. "Who made this decision Andrew? You are aware that we have the highest solve rate in the entire FBI?" Brennan waited, slightly impatiently, as Hacker paused before answering. "He did? Did he say why? He just thought it was time for a change… Thank you Andrew." O'Brien's thoughts were in overdrive. 'He? Did that mean someone up the chain from Hacker? Or could it have been Booth himself?' O'Brien couldn't believe it would be Booth because he seemed very emotional about handing over his partnership with Doctor Brennan. And then there was the way he bolted from the office after giving him the Brennan treatise. No, it couldn't have come from him.
Brennan carefully set down her phone and O'Brien wasn't sure what to make of the expression on her face as she rose from her chair. It was mostly stoic, and her beautiful blue eyes looked slightly dead. "Agent O'Brien, I'm sorry I can't spend more time with you today, but I have some things to deal with. Please leave your number and I will get back to you." He stood up, reached into his inside pocket, pulled out a business card, and set it on her desk. "I hope to hear from you soon Doctor Brennan. I'm really looking forward to working with you and your team." Brennan nodded silently to him and he turned and left her office.
Once he was gone from her view, she fell back into her chair. She felt like her head was about to implode. Booth requested this change? She knew that things were different between them since Hannah had arrived on the scene, but their work had never suffered. He had been pulling away from her gradually, but she never would have anticipated him wanting to sever the partnership. She continued to stare off into the distance and couldn't focus her vision on anything in particular while her brain went into overdrive. 'Why? Why? Why?' went over and over in her head while visions of working together on recent cases flashed before her eyes, looking for a clue. Something, anything that could have been the catalyst.
And then it all stopped. It was like a lightning bolt in her head. 'When did he make this decision?' She thought about the last time they talked. It was the previous Thursday - six days ago. They were at Founding Fathers celebrating the closing of their most recent case. As usual, Hanna had joined them, but after one drink she said she was tired after a long day and she and Booth left. Brennan stayed and had two more drinks and chatted with their favorite bartender before heading home herself. She wracked her brain trying to remember what the three of them talked about in the short time they were there, but nothing out of the ordinary came to mind. Was there anything unusual that day working together on the case? She had nothing. The more she thought about it, the angrier she became. He must have made this decision sometime in the last six days. He made the decision, went to his boss to set up the agent reassignment, a decision was made to pair her with Agent O'Brien, and he was notified of the change. All of that happened with no consultation with her. Even so, she deserved a visit from him explaining what he had done - and why. After almost six years of working together she deserved at least that much. She had always considered Booth an honorable man. This was so out of character that she could hardly believe he was capable of betraying her in this fashion. She deserved an explanation. And she was going to get it.