Season 4 - Episode Guide

When Brennan and Booth go to London to guest-lecture at Oxford and Scotland Yard, local officials ask them to help investigate the murder of a young heiress; Angela's long-estranged husband returns.

Having solved the murder of a wealthy American's daughter, Brennan and Booth are persuaded to remain in London when one of their English colleagues is killed.

When the corpse of the host of a popular reality show is found partially decomposed in an outhouse, Brennan and Booth must separate the killer from many suspects; Booth discovers that Brennan juggles two relationships.

When Booth's son, Parker, finds a finger in a bird's nest, the team launches an investigation to find the rest of the body; Booth asks Sweets to psychoanalyze his son; Sweets confronts Hodgins about his attitude in the lab.

A teen discovers a dismembered, headless body in a pool of purple water; the team struggles to find enough evidence to locate a killer until getting insight from Zack, who studies the case at his psychiatric facility.

Booth and Brennan investigate when the remains of a disliked office manager are found in a building elevator shaft; Angela and Hodgins try to figure out their altered relationship.

Skeletal remains with remnants of breast implants are found in the Chesapeake Bay; when the body's lower half is discovered, the team realizes that initial assumptions about the victim may be wrong.

Booth and Brennan investigate when the remains of a renowned artist are found in an impounded junkyard car; a woman connected to Angela becomes a suspect in the case.

A con man misleads the team during a murder investigation; Booth's younger brother, Jared, takes a job at the Pentagon; Brennan agrees to go on a date with Jared to a White House function.

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 and Booth investigate when a skull and other skeletal remains are found in a nationally protected wooded preserve; Brennan's recently acquitted father finds a job as a teacher.

A shallow grave holds the remains of conjoined twins; Booth and Brennan infiltrate a circus community after they discover that the twins were jugglers there.

A man and his son discover a frozen body in a pond; Booth gets advice from one of his hockey idols.

Brennan and the team get a phone call from the Grave Digger, who informs them that Booth has been buried alive with only 24 hours of oxygen.

The team investigates at a fantasy convention when a female science-fiction enthusiast is found murdered.

While bungee-jumping, a couple discover a corpse at the bottom of a gorge; the lab goes into lockdown when an unknown substance begins oozing from the cadaver.

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 convinced the death was no accident after the half-eaten body of Cam's ex is found in the tiger cage at the zoo, leading the team to hypnotize one suspect to try to jog his memory.

Booth and Brennan investigate when pulverized human remains are found in a garbage bag; Angela's father seeks revenge on Hodgins.

A flattened body is discovered in a bale of compressed cardboard; Booth and Brennan get suspicious when they see Sweets' girlfriend with another man.

Booth and Brennan look for a killer and a motive when it is discovered that a human skeleton is being used as a prop for a death metal band.

Brennan is suspicious when a Jeffersonian co-worker dies of heart failure; Cam tries to get her newly adopted teenager to stop smoking.

A friend of Booth's, Ken Nakamura, asks for help when his sister goes missing in Washington.

The body of a fraternity brother is discovered inside a rival school's mascot uniform; Booth tries to help his brother find a new job.

Brennan asks Booth to be the father of her child; Stewie Griffin offers the couple advice.

When a body is discovered at a popular nightclub, everyone is a suspect.