Bones reluctantly searches for a replacement for Zack. A skull is tossed off a highway overpass and hits a vehicle. There is evidence the victim was eaten by a cannibal.
The discovery of two mummified girls has Booth and Bones checking a fun house, a Halloween maze and a church charity for clues that may lead them to a missing girl whose parents believe she's dead.
The Gormogon killer strikes again, and his next play is a little close to home. Russ returns to face a parole violation when his girlfriend's daughter takes a turn for the worse.
Brennan and Booth investigate the death of a Santa as Bones tries to give her father the Christmas he's always dreamed of, and Booth comes to terms with not spending the holiday with Parker.
Booth and Brennan investigate the death of a motorcycle racer, and when another seeming accident occurs on the track attention turns to the team owners and a reporter, meanwhile Dr. Sweets manipulates them into a "social outing" with him and his girlfriend.
Miraculously surviving a suspicious car accident that kills its mother, a baby is left with Booth and Bones who care for the infant while investigating the crime.
Brennan's father Max goes on trial for the alleged murder of FBI Deputy Director Robert Kirby, requiring everyone on the Jeffersonian team but Brennan to testify for the prosecution. Brennan, the forensics advisor for the defense, desperately tries to prove her father's innocence. Meanwhile, Booth requires the assistance of therapist Dr. Lance Sweets to help with his partnership with Brennan.