After a skull smashes into the windshield of a teenager's car, the investigation reveals the skull has been gnawed on by human teeth, which implies cannibalism and marks the beginning of the Widow's Son case. Meanwhile, Angela and Hodgins hire a private investigator to find her husband. Bones searches for Zach's replacement and the team gets a wonderful surprise.

When a body that appears to be cooked is discovered, the clues lead Booth and Bones to an organic farm co-op. Meanwhile, the two of them must meet with Lance Sweets, an FBI psychologist who must determine if they should continue to work together.

On the 20th anniversary, the Foothill High School, class of '87 alumni unearth the time capsule they buried to discover the remains of one of their classmates inside. Booth and Bones investigate the past lives of his classmates in an effort to discover the truth.

Booth and Brennan investigate a mall Santa named Kris Kringle who was found dead by two elves. A series of clues makes the murdered mall Santa seem like he's the real deal.

Brennan's father Max Keenan is on trial for the alleged murder of FBI Deputy Director Kirby. Everyone on the team, except for Brennan, is called as a witness for the prosecution during the trial. Brennan on the other hand is the forensics advisor for the defense, and she must rely on both her dedication to her family and her skill as an anthropologist to help free her father.

Season four begins all the way in England, with Booth speaking at Scotland Yard and Brennan guest-lecturing at the prestigious Oxford University. Knowing of Booth and Brennan's expertise in their respective fields, local officials ask for their help with a high-profile murder investigation that involves a British heiress.

With the case of the murdered heiress solved, Booth and Brennan prepare to head back home, but are shocked to learn of another murder - and this time it's someone they know. Meanwhile, with Birimbau unexpectedly coming back into Angela's life, things get complicated between her and Hodgins.

The body of the host of a popular reality TV show is found partially decomposed in an outhouse, and Booth and Brennan must find out who the killer is. Meanwhile, Booth learns that Brennan is juggling two relationships.

While en route to China to identify prehistoric anthropological remains, Booth and Brennan are called upon to solve a murder in midair when the flight attendant discovers a fully cooked human body in the plane's microwave.

Brennan's father Max lands a teaching position at the Jeffersonian. When he ends up helping out with the murder case at hand, Brennan is noticeably bothered by his sudden presence in her professional life.

While trapped and trying to escape from a ship in the middle of the ocean, Booth is haunted by strange hallucinations.

The body of a pregnant 16-year-old athlete found buried in a mound of salt in a city de-icing truck leads Booth and Brennan to the discovery that many of her teammates are pregnant or have babies after a pregnancy pact.

Booth and Brennan are called when an image of the Virgin Mary is found in a bale of compressed cardboard.

Booth's detective friend from Tokyo, Ken Nakamura, calls him when his sister, Sachi, goes missing while in Washington, D.C. With Brennan, Booth investigates her disappearance.

In the season finale, a dead body is found at a club called "The Lab." The team has to do some unexpected and unusual things that have to do with this club. Brennan and Booth may become a couple.

When human remains are found alongside the railroad, Brennan and Booth are called to the case. The bones belong to Levi Yoder, a member of the Amish community who disappeared two months ago, during his Rumspringa, or exploration of the outside world. Brennan and Booth discover that Levi was a piano prodigy, and their investigation leads them to believe that his extraordinary talent may have lead him to an untimely death. Meanwhile, Cam copes with the stress that comes from being a new parent.

Remains of a chicken farmer are found on the bank of a nearby river, and Booth and Brennan are called in to investigate. The farmer, who was an animal rights activist, was about to inherit a chicken factory and had many enemies with motive to kill him – leaving the team with a lot of murder suspects to sort through.

When the remains of a competitive gamer are discovered in a grease truck, Brennan and Booth are called to investigate the case. The victim, Steve Rifton, is the only active player known in the gaming community to have received a perfect score on a famous video game. Steve turned his success into a lucrative partnership with a gaming referee and charged fans to play on the very machine that gave him the perfect score. But between sour business deals and bitter competitors, the team at the Jeffersonian must work to narrow down the many suspects with motive for ending Rifton’s reign as gaming king. Meanwhile, Hodgins, Sweets and Jeffersonian intern Colin Fischer take turns camping out for tickets to a movie premiere.

Mr. White and his team of government agents put the Jeffersonian Lab on lock down and demand that Brennan and her forensics team determine a cause of death for an unidentified, but highly classified set of remains. As the team gets to work, their findings lead them to suspect they are investigating one of the most famous presidential assassinations in history. Meanwhile, Booth's boss, Andrew Hacker, helps him break into the lab and determine the motive behind the mystery investigation, and a frustrated Cam worries that Michelle may be keeping a big secret from her.

When a subway train is thrown off the track by 60,000 gallons of flood water, a partially skeletonized body emerges out of the overflow. While Dr. Sweets, a passenger on the derailed train, copes with post traumatic stress, the rest of the team and intern Daisy Wick get to work on identifying the victim as Martin Aragon, a professional ghost writer caught up in a deadly love triangle. Meanwhile, Brennan releases her second book to great success, but has to accommodate a nosy reporter, and Sweets' near-death experience leads him to make a drastic decision.

When human remains are discovered in the belly of a shark, Brennan and Booth are brought in to identify the missing person. Evidence suggesting the victim had been the prey of several fish directs the team’s investigation to The Aquarium of the Atlantic, where a guest lecturer and notorious self-help guru preaching the healing power of the ocean has gone missing. Meanwhile, both Brennan and Booth navigate their own relationship when a marine biologist shows interest in Booth.

The trial of The Gravedigger hits close to home for members of the team, and everyone at the Jeffersonian must work overtime to uncover the forensic evidence to elicit a conviction.

When the remains of a couple are discovered in a cave at National Park, the team must piece together the identity of the man and the woman as well as solve the crime. After interrogating two viable suspects, the team identifies the woman as a marketing executive who also served as her partner’s AA sponsor, providing clues that lead them to expose the truth. Meanwhile, Booth’s girlfriend and Afghanistan war correspondent, Hannah Burley, makes a surprise visit. After meeting Burley and sensing the couple’s genuine happiness, Brennan re-evaluates her own relationship with Booth, and he tries to teach her that love is not always logical.

After the skull of a promising young dancer is found lodged in concrete at a construction site, the team must first figure out what happened to the victim’s skeletal structure. After learning the victim quit ballet to pursue hip hop, Booth and Brennan uncover another layer of evidence that points them to a suspect who had a secret relationship with the victim. Meanwhile, when Hannah is put on assignment in a dodgy part of town, her safety is jeopardized and her life is put in critical danger.

Brennan gets a glimpse into her own life when the body of a brilliant and career-driven surgeon is found in a rough neighborhood with multiple fractures in her skull and no indication as to how or why she was there. While the team investigates the case objectively, Brennan struggles to separate her own life from the victim’s as she perceives many parallels between them the more she learns about the victim’s past. Meanwhile, evidence found at the crime scene brings the team closer to solving the case, but it’s Brennan’s unique perspective that propels her to retrace the final events of the victim’s life. With the reassurance of a new friend and Jeffersonian security guard, Micah Leggat, Brennan makes a discovery about herself and learns a lesson about taking chances.

An unidentifiable body is discovered in the shower of an upscale home belonging to a young female socialite. With the help of nosey bones expert and Jeffersonian “squint” Clark Edison, skeletal reconstruction and evidence in the drain reveal that the victim was a young girl employed by a counterfeit handbag distributor. The team learns that the victim supplied counterfeit purses to her socialite acquaintance, and after interrogating the self-centered socialite and sifting through footage on a hidden camera, they discover evidence linking them to the murderer. Meanwhile, Angela and Hodgins discuss their future home and where they want to raise a family, and Booth opens up to Hannah about Brennan’s feelings for him

The liquefied remains of a wedding planner are found in her home tanning bed on Valentine’s Day, and Cam pressures her team to solve the case in time so she can celebrate the holiday with her boyfriend. While the “squints” works tirelessly in the lab, Booth and Brennan interrogate a slew of possible suspects until they unlock classified files in the victim’s computer, which lead to their main suspect. Meanwhile, Booth and Brennan downplay the significance of Valentine’s Day, and Hodgins tries to plan a romantic day for Angela, but “squint” Clark helps him realize that the most meaningful gifts come from the heart.

Brennan teams up with a Canadian forensic podiatrist to determine the real victim after eight pairs of feet are found washed up on the U.S.-Canadian border, but seven pair belong to research. Elsewhere, Cam crosses a major boundary when she takes away Michelle's right to choose her own college.

When a 15-year-old Jane Doe is found on the streets, it is up to Brennan, Jeffersonian Intern Arastoo Vaziri and the entire Jeffersonian team to figure out her history and if she is responsible for a recent murder

Dismembered remains are discovered in several mailing boxes at a dead letter office, and the Jeffersonian team identifies the victim as an employee of a local Ship 'n' Print, where the staff recently split the winnings of a lottery prize. The team uncovers a complicated love triangle between two married employees and the victim, and while motive points to the husband a critical clue leads them to solve the crime definitively.

The remains of an escaped convict are found in a residential sewer, but an examination of the sewer pipes indicates that the murder occurred within prison walls. Brennan insists on solving the crime despite Booth's pleas for her not to overexert herself and the expectant couple experiences a very untraditional arrival of their baby daughter.

The corpse of a truck company employee is found in the middle of the woods. After the victim’s son is questioned, Booth and Brennan visit his karate class in search of a motive. Back at the lab, Hodgins is going overboard purchasing lab equipment. Then, Booth’s son Parker returns from England and Brennan is apprehensive about how he’ll react to his new baby sister.

"Hacktivist" and suspected serial killer Christopher Pelant is back in court, but the team's efforts to pin another murder on him don't go as planned.

The Jeffersonian team investigates the murder of a high-powered divorce lawyer with a lot of enemies. The plot thickens when the team discovers that the attorney's wife and assistant have been hiding crucial evidence which could help solve the case. Meanwhile, Brennan tries to adjust to life after being on the run, and tensions start to rise between her and Booth as the impact of their three-month separation begins to take its toll.

The remains of a crime scene cleanup expert are found sealed in a mysterious pod that washed up on a beach. Meanwhile, Angela and Hodgins have reason to believe that Cam has a secret lover.

A street artist who is plastering his work on a billboard falls into his glue—and onto a corpse—so the team try to get him unstuck from the remains as they also work to identify the body. Meanwhile, Booth takes a stab at stand-up comedy at a club's open-mike night to look for suspects; and Angela finds herself attracted to the street artist.

The Jeffersonian team investigates the remains of two bodies that were found at the same burial plot: one of a female cancer patient; the other, the cancer patient's "doula," who was guiding her through her grieving process with the illness. Meanwhile, with a spotlight on the case, Brennan and Booth start discussing their individual choices for after-death arrangements. Also, Daisy Wick returns for her first case after her break-up with Sweets.

When Brennan is shot while working late at the Jeffersonian lab, she is rushed to the hospital in critical condition. While at the hospital, she struggles with visions of her mother that defy her usual logic. Meanwhile all evidence suggests that Brennan's attacker may be linked to the Jeffersonian.

The Jeffersonian team investigates the death of Symchay Conteh, a young man whose remains were found in a barrel at a hazardous waste disposal facility. They discover that the victim was an immigrant from Sierra Leone working numerous part-time jobs in order to make ends meet. Meanwhile, as the team gets deeper into the investigation, Cam and Arastoo find it even more difficult to keep their relationship a secret and Brennan and Booth try to decide on a vacation destination.

The Jeffersonian team investigates the murder of a TV producer. Meanwhile, Brennan has trouble accepting the fact that Christine might be an "average" child, when her daughter gets accused of biting another classmate. Then, Hodgins uses all of his tools at the Jeffersonian to chemically recreate Finn's special hot sauce.

When evil tech genius Christopher Pelant returns to toy with the Jeffersonian team in their newest investigation, they discover that the string of murders that have been occurring are tied to FBI agents close to Booth. Meanwhile, as the investigation unfolds, Sweets realizes that the evidence seems all too familiar to him and Brennan starts evaluating her relationship with Booth when signs begin to point to him as a potential target of Pelant's.

The Jeffersonian team investigates the murder of Jason Siedel, an accountant for the state department, whose remains were found in a hotel air conditioning unit. When Booth finds his old army buddy and CIA agent, Danny Beck, clearing away evidence at the victim's condo, he begins to realize that Siedel's murder could yield more suspects than the team had anticipated. Booth also seeks out Aldo Clemens, his friend and an ex-priest from their military days together, to get advice on his relationship with Brennan, now that Pelant has put a wedge between them. Meanwhile, Brennan must decide whether to have faith in Booth or to end her relationship with him.

The team investigates the murder of a high school principal who was dying of cancer; Brennan and Booth plan their wedding; a virtual profiling system threatens Sweets' job.

A key witness turns up dead in a case for which Brennan is a juror, so the team works to discover what has happened.

The team investigates when the remains of a girl who died 18 years earlier are delivered to Brennan and Booth's house; Brennan dreams about Pelant.

The Jeffersonian team investigates the murder of Lauren Frank, a kidnap victim whose remains were found buried at a park. But when they discover the unhappy relationship that Lauren had with her stepmother, the team starts to think the killer was someone closer to the girl than expected. Meanwhile, Hodgins uncovers a shocking secret about his family and Brennan and Booth face a common couples dilemma - whether to co-mingle their funds.