When a woman’s burned body is found in a car with signs that her child was kidnapped, Brennan and Booth suspect the father, Carl Decker. But things get complicated when Decker turns out to be in the Witness Protection program.

Booth and Brennan investigate the death of Terence Bancroft, one of the Jeffersonian's major donors, found dead at his home. Hodgins' relationship with the wife of the deceased years earlier, compromises the case.

After the body of an archbishop is found, missing the kneecaps, the team concludes the murder is related to the Widow's Son case.

When a human skeleton is discovered in the trenches of an old Civil War battleground, Brennan and Booth are called to the case. Despite the historical location, Brennan quickly identifies the bones as belonging to Dan Pinard, a present-day local dentist. While Booth investigates suspects, including the victim’s former boyfriend, Hodgins and lab intern Vincent Nigel-Murray work doggedly to clean the bones of a stubborn clay residue which is preventing the team from determining a cause of death. Meanwhile, Booth’s brother, Jared, returns from his travels with some suprising news.

The team's investigation of the death of an animal expo worker leads them into the shady market for illegal animal trading. Meanwhile, Brennan considers her political aspirations; and Sweets and Daisy confront a change in their relationship.

When extremely educated new intern Dr. Oliver Wells (Brian Klugman) starts working at the Jeffersonian, his quick-learning, enthusiastic personality challenges Brennan as he gets under her skin with his eccentric but undeniable observations, causing her to try to be more open-minded about many scientific questions. Meanwhile, Booth worries she may have gone too far when she accepts the possibility of time travel as a factor in a murder investigation.

Aubrey works alongside the team to investigate a government conspiracy. DNA found on a previous victim helps the team to narrow down the suspects.

The case of a maid's death turns out to be a bigger case than originally thought. Tensions are rising between Cam and Brennan.

Booth is still missing, but the team learns that Agent Miller has hidden information about his whereabouts and physical state. Meanwhile, a digital forensic scientist helps Angela try to decipher information pertaining to Booth's location and the circumstances of his disappearance; and Arastoo makes a decision that will change his and Cam's personal and professional relationships.

A drunk college student discovers the dead body of a Secret Service agent just before a presidential visit to the area. Booth is ready to hit the ground running and turns to Secret Service agent and former colleague Brandt Walker for information, but is surprised to learn the Secret Service has reservations about Booth’s involvement in the case. The team uncovers some shocking evidence that heightens the seriousness of the case, causing Booth to step up for his country. Meanwhile, Brennan is out sick with the flu and former intern Dr. Colin Fisher returns to the Jeffersonian to run lead on the case, but Brennan refuses to be kept out of the loop. Also, Hodgins takes his life into his own hands and turns a corner after a potentially dangerous experiment.

When a tutor of privileged students turns up dead, the team sorts through all the possible perpetrators, from disgruntled parents to the tutor's roommate with a criminal record. Meanwhile, Bones is frustrated with the voice of her audio book and tries to prove that she can record it herself.