Episode 23 of "Bones"
s02e01 The Titan on the Tracks

Brennan and Booth investigate the site of a train wreck where the bodies of a senator and a high-profile businessman are found within the wreckage. The businessman's body is found in a car on the train tracks, and at first glance, it is an apparent suicide. While investigating a possible connection between the two victims, Brennan and her team discover the businessman is still alive, but severely injured, at a local hospital, and the body at the scene is someone else. As the clues begin to unravel, the investigation gets more complicated when details of the man's private life are revealed, leading Brennan and Booth to a private detective who may hold key information. Meanwhile, Brennan is introduced to Dr. Camille Saroyan, a first-rate pathologist who has been hired as the head of forensics at the Jeffersonian, and more importantly, Brennan's boss. It doesn't take long for Brennan to figure out "Cam" is a little too familiar with Booth and that they share something of a past. Also, Booth encourages Brennan to visit her mother's gravesite for the first time.