Nathan Dean

After construction workers find the body of an archbishop whose kneecaps were surgically removed, the team is back on the case of the Widow's Son serial killer. When Angela discovers what appears to be a victim tree in the evidence vault, the team realizes the killer employs a systematic pattern in selecting victims. With a musician and an archbishop the first to go, the team tries to predict who might be next and how they can stop the killer before he strikes again. Brennan and Booth continue to see Dr. Lance Sweets (John Francis Daley), who has some helpful psychological insights into the Widow's Son's motives. Meanwhile, Brennan's brother, Russ, comes out of hiding when he finds out that his girlfriend's daughter is extremely sick, but his appearance causes Booth to intervene with Brennan's family once again.

After Booth has a bedroom romp with his ex-girlfriend Rebecca, he gets a call from Brennan about their latest case and agrees to meet her at a condominium construction site. They're led into a partially built unit where they find the gruesome remains of a man dissolving in a bathtub of household cleaning products. After determining the victim had Brittle Bone Disease, they search a database of area BBD victims, all of whom are children, and split up to visit them in hopes of finding a connection to the dead man. When both Brennan and Booth come back with confirmation of the man's identity, they realize he was living a double life with two different families. In what first appears to be a straightforward case of jealousy and insurance money, new clues send Brennan and Booth in a completely different direction and a third suspect is brought to light.

A group of teenagers are driving on the freeway when a skull smashes through their windshield. At the Jeffersonian lab, Brennan tests out a young forensic anthropologist to replace Zack, who has left for Iraq, and she and Cam examine the skull in question. They find it has marks made by human teeth, suggesting cannibalism. The team identifies the victim, a known violin protégé who disappeared after a concert. On a quest to find out what happened to him, Brennan and Booth go into the field. A trail of suspects leads them to a strange cannibalistic society, and the team must string together a gruesome and cryptic series of crimes - provided that Brennan and Booth can survive the newfound tension between them. Meanwhile, Cam suggests that Angela hire a private investigator to track down her ex-husband so she can annul her previous marriage and marry Hodgins, a task easier said than done.

Booth and Brennan investigate the scene where a car was run off the road and the victim's body deliberately burned beyond recognition. When the team hears muffled whimpering during the site investigation, they find the victim's baby miraculously perched in a tree above the scene of the crash. The team designates Brennan as the infant's caretaker, but when the baby swallows a key piece of evidence, they question her nurturing skills. The team soon identifies the victim as a laborer who worked in a tire-recycling factory in a small, impoverished town in Virginia, and Brennan and Booth venture out to investigate who might have wanted her dead. Their suspicions range from her deadbeat husband to the impecunious habitants of her town. Meanwhile, the team is fascinated by the presence of a baby in the lab and its affinity for Brennan.

Brennan and Booth visit a college campus where human remains are found under the bleachers of a basketball court. Although the body had been crushed beyond recognition underneath the bleachers, a gold "#11" necklace identifies the victim as RJ Manning, the star point guard of the school's nationally ranked basketball team. After reconstructing RJ's skull, the team determines that he was dead before the bleachers crushed him. Brennan and Booth navigate the world of big-time collegiate basketball and interview multiple leads to find out who could possibly have benefited from RJ's demise. After investigating those with the closest ties to RJ, including his faithful girlfriend, his future basketball agent and his replacement on the school's team, Brennan and Booth uncover several different plausible motives for RJ's murder. Later the team discovers that RJ may have been caught up in a rather risqué situation at the time of his death, and they wonder if more than one person could have been involved in his murder. Meanwhile, Hodgins attempts to take his relationship with Angela to the next level, but his courting methods prove to be far less tactful than his scientific ones.