Forensic anthropologist Temperance "Bones" Brennan and her team work with the FBI to solve murders by identifying victims from their remains in a procedural series inspired by real-life forensic anthropologist and novelist Kathy Reichs.
Part 1 of 2. Brennan and Booth are on a lecture tour in London, where their trip is extended after they're drawn into the investigation of the murder of a wealthy American's daughter. Meanwhile, back at the Jeffersonian, Angela is surprised by the return of her estranged husband, who must agree to a divorce before she can marry Jack.
The gruesome death of the host of a reality-TV show that exposed infidelity challenges the Jeffersonian team to identify a killer from a long list of disgruntled adulterers who may have been motivated by revenge. Meanwhile, Booth is surprised that Brennan is dating two men at the same time.
The discovery---not far from the Jeffersonian---of the mutilated body of a veterinarian leads to an investigation that uncovers the deceased's gambling addiction and possible ties to an illegal dogfighting enterprise. "Dog Whisperer" Cesar Millan guest stars.
When the murder of a reclusive science-fiction writer with obsessive-compulsive disorder has the Jeffersonian team stumped, Hodgins turns to Zack (Eric Millegan) for help in piecing together the evidence to track down the killer.
When the mangled corpse of an office manager is found in an elevator shaft, Brennan and Booth probe the complexities of the company's politics to find out if any of the numerous grudges borne by her former coworkers shed light on her tragic death. Meanwhile, Hodgins and Angela have a long-delayed discussion about their breakup.
Brennan and Booth alight in a small religious enclave on the Chesapeake Bay when the remains of the community's pastor are discovered, but they have their work cut out for them in determining the true identity of the victim and a possible motive for murder.
A sculptor's corpse is found in a crushed car at a junkyard, and the team must decide if it's the result of the dead man's artistic suicide or murder. The case is complicated by the fact that his assistant---Angela's ex-girlfriend---is a suspect.
The discovery of a body at a state-police training site leads to the investigation of a confidence game, played on a struggling inventor, that resulted in a pair of murders. Meanwhile, Booth's brother (Brendan Fehr) takes a job at the Pentagon and develops a crush on Brennan, and Hodgins and a returning Clark Edison test the viability of the inventor's designs.
On a trip to China to inspect prehistoric remains, Brennan and Booth try to solve the airborne murder of a travel writer, but the pair must find the killer before the plane lands in Shanghai and takes the case out of U.S. jurisdiction. Meanwhile, Hodgins tries to come to terms with Angela's new relationship.
As Brennan struggles to accept the hiring of her estranged father (Ryan O'Neal) as a teacher at the Jeffersonian, the team searches for clues in the murder of a former Marine who was working as a nanny for a wealthy family.
Brennan and Booth go undercover to join the circus as a knife-throwing act to determine who might be responsible for the deaths of conjoined twins, and the list of colorful suspects includes the ringmaster (Andy Richter), a strong man and clowns.
Booth may face a trip to a different kind of penalty box when he becomes a suspect in the murder of a rival ice-hockey player with whom he has a history of fighting, and Brennan gets a new FBI partner (Marisa Coughlan) for the case. Former NHL great Luc Robitaille guest stars as himself.
Missing evidence from the Grave Digger investigation arouses suspicion of Brennan, Hodgins and an author who wrote about the case, but a judge's inquiry takes a backseat after the sepulchral serial killer reveals that Booth may be his latest victim.
Agent Perotta (Marisa Coughlan) pitches in when the Jeffersonian team investigates the death of a female science-fiction fan, which leads to a visit to a convention for aficionados of comic books and video games. Colin: Joel David Moore.
A corpse discovered at the bottom of a gorge throws the lab into a panic when its bones begin to disintegrate, and Brennan and Booth must hurry to find the killer after they learn that the victim was a shady car salesman. Directed by David Boreanaz, who plays FBI agent Seeley Booth.
The discovery of the body of a high-school athlete in a municipal salt truck is linked to news reports of a "pregnancy pact" with the deceased's volleyball teammates. Meanwhile, the prospect of adopting a dog tests Angela's relationship with Roxie (Nichole Hiltz).
A hospital charity event at a zoo ends in tragedy when the mutilated body of a doctor is discovered in a tiger cage, and the case gets personal for Cam when she reveals that the deceased is her former fiancé. Meanwhile, Angela struggles to keep her vow of celibacy. Chad Lowe guest stars.
The death of a physicist leads Brennan and Booth to a well-known research institute, where the deceased had been part of a controversial study that was likely the reason for a number of threats against her life. Meanwhile, Sweets intervenes when Angela's father, ZZ Top guitarist Billy F. Gibbons, comes looking for Hodgins.
When a bride-to-be's body is found in a bundle of compressed cardboard at a recycling facility, Brennan and Booth use records from a cell-phone dating service to search for suspects from a long list of potential suitors. Meanwhile, Sweets' girlfriend, Daisy, is spotted shopping for a wedding dress.
The Jeffersonian team's musical preferences are revealed when Brennan and Booth reluctantly scour the death-metal scene after the discovery of an actual human skeleton being used on stage by a band in Norway. Meanwhile, Sweets' colleague Dr. Wyatt (Stephen Fry) shares his insight on Brennan and Booth's partnership.
Brennan is skeptical when a Jeffersonian colleague supposedly dies of natural causes, and she asks Booth to help her "borrow" the corpse so she determine the real cause of death. Meanwhile, Cam has trouble getting through to her newly adopted daughter about the dangers of smoking.
Booth helps a detective friend from Japan after the man's sister goes missing in Washington, D.C. During the ensuing investigation that leads to an escort service, Booth and Brennan discover the woman's roommate has also disappeared.
The body of a fraternity member is found inside the costume of a rival university's mascot, but Brennan and Booth may not find a whole lot of brotherly love for the deceased when they learn that he was a BMOC---or big moneymaker on campus. Meanwhile, Booth tries to return a favor for his recently unemployed brother.
Stewie Griffin (voice of Seth MacFarlane) of "Family Guy" appears to Booth after Brennan floats the idea of becoming a mother---and wants Booth to be the father. Meanwhile, the body of a wine critic is found inside a barrel at a tasting.
In the fourth-season finale, a murder at a nightclub where Mötley Crüe, who appear as themselves, are performing makes suspects out of the entire Jeffersonian team, who go to extremes to solve the case and clear their names. Guest stars include Eric Millegan, Ryan O'Neal and Brendan Fehr.