At Rock Creek Wild Life Park, the caretakers find a corpse in the tiger cage. The victim is a black male. At the lab the team finds that the tiger did not kill this man; he bled to death. Someone cut his femoral artery. Hodgins pulls a shoelace from the remains as Angela arrives. She notes that Clark looks "squeezable." Angela's attempt at celibacy is just making her randy, much to Clark's discomfort. The victim is Dr. Andrew Welton… who Cam lived with for two years. Cam wonders about Welton's daughter, Michelle, who was like a daughter to her as well. She insists on visiting Michelle herself to give her the news, but Michelle doesn't remember Cam. Cam tries to console her, but Michelle pushes Cam away. Cam is heartbroken.

Hodgins and Clark discover particles of mica and other small white flecks. Clark theorizes that the murder weapon gouged the victim. Cam reluctantly reports that Welton had opiates in his blood, but insists that Welton was not a drug abuser. There must be some reason Welton needed medication. At Roosevelt Hospital, Cam and Booth talk to Dr. Maura Bailey, the Chief Administrator and an old rival of Cam's. Booth tells Bailey that they believe Welton was killed at Rock Creek Wild Life Park during a hospital benefit on Friday night. They need a list of all attendees. Booth also asks for a list of any malpractice suits against Welton. Cam and Booth then question nurses Nancy Lauder, Gretchen Kujawa, and Lauren Dobbs. They tell Booth and Cam that nothing unusual happened before Dr. Welton went to the benefit. Did he have a date? Dr. Welton could have taken anyone to the party. "He wasn't the type to settle down," comments Nancy.

At the lab Angela finds Hodgins working with a sample from the victim's clothing. Angela likes the smell. Hodgins tells her it's tiger urine. She realizes celibacy is doing strange things to her. Hodgins suggests she join a gym to burn off the excess energy. Brennan finds bony growths on Welton's thumbs. He had synovial chrondromatosis, a condition that requires painkillers. It would have made it dangerous for Welton to operate. It turns out that a man named Brandon Casey sued Dr. Welton because his wife died during an operation. Dr. Welton won the lawsuit, and filed a restraining order against Casey; yet Casey bought a ticket to the hospital benefit. He was there the night Welton was murdered. Casey is interrogated. He admits he was angry after his wife died, but he later saw that he was wrong, and went to the benefit in order to apologize to Welton. They never got a chance to talk because Welton was arguing with a woman. Booth asks for a description, but Casey can't remember anything about her. Sweets believes they can retrieve the information through hypnosis.

Brennan and Clark find defensive wounds on the bones. Angela appears, again flirting with Clark, who tells her his sexual needs are fulfilled. Angela says the injuries were caused by someone between 5'7” and 5'11”, brandishing a five-foot pole. Later Sweets hypnotizes Casey, with Angela there to sketch the woman that Casey describes under hypnosis. When Booth and Cam show the sketch to Bailey, she recognizes the woman as Diane Annenburg, one of the hospital's generous donors. Was Annenburg upset that Welton was operating while ill? Bailey clarifies that Welton was no longer operating: he was supervising. Bailey says Diane was upset that Dr. Welton rejected her son Rick's application for a surgical residency. Booth interviews Diane, who says her argument with Welton was simply about how disappointed she was that her son would not be participating in the residency program. Her son deserved to be in the program: he was second in his class. Annenburg wanted Welton removed from the Board of Admissions, but she would never kill him. Perhaps not, but would her son?

Brennan asks Cam about Michelle; Cam guesses they will move her to a foster home. Hodgins reports that the small white flecks from the body are bits of a plastic knife. Cam remembers that they found a shoelace in the remains. Perhaps the killer tried to save Welton. He used a plastic knife to enlarge the wound and the shoelace to tie off the femoral artery to stop the bleeding. Despite its failure, the procedure suggests that the killer has medical knowledge. Rick Annenburg is questioned. He claims that Welton helped him by rejecting him from the residency program at Roosevelt. Now he can go to a program elsewhere, and get away from his mother. Rick knows that if someone tried to tie off Welton's femoral artery, they would be covered in blood. He wasn't: he's innocent.

Cam visits Michelle, and shows her a picture of the three of them together: Cam, Michelle, and Dr. Welton. Michelle admits that she remembers Cam, but is angry and upset with her for leaving. She thought Cam loved her; she thought they were a family. She waited every day for Cam to come back. Cam tries to explain that she and Welton were going to get married, but Welton was still seeing other women. He couldn't commit to Cam, so she had to leave. Michelle suggests that maybe Cam just wasn't good enough for her father, and she tells Cam to go. After Cam walks away, Michelle breaks down in tears. At the lab Angela and Brennan have coffee with Cam. Cam describes what Michelle said, and why she left Welton. Brennan realizes that if Welton cheated on Cam, he could still be seeing more than one woman.

Hodgins reports that the urine on the victim's clothes came from a lion, not a tiger. What's more, what he thought was mica turned out to be snake scales. There are no lions in the park, but their urine is used to keep the capybaras in their enclosure. Near the capybaras, there is a reptile shed. In the photograph, Brennan sees a snake hook. This could be the murder weapon. Clark brings a visitor to see Angela in her office: Dr. Nora Oldhouse, Clark's "romantic partner." He hopes this will help Angela see that he is unavailable, and that her advances are unwelcome. An understanding Dr. Oldhouse offers Angela advice: "In the absence of a sex partner, there are other alternatives. Vibrators or sex toys..." Clark, aghast, excuses himself. Dr. Oldhouse happily confirms to Angela that although Clark's tightly wound, he's a "briefcase bomb" in bed.

Langston, the clerk at the motel Welton and Cam used to frequent when they wanted to get away during work, tells Cam and Booth that Welton had been frequenting the motel with someone else as of late: Dr. Maura Bailey. At the FBI, Booth and Brennan show Bailey the snake hook. Bailey says she's never seen it before. Booth wants her to prove it by letting them test the clothes she wore to the benefit. Bailey declines. They don't have a warrant. Brennan mentions that they know about her affair with Welton, and they'll talk to her husband, but Bailey won't be blackmailed. Booth and Brennan can talk to her through the hospital's lawyer from now on.

Cam sits in the lab with a salt-and-pepper shaker. Brennan approaches to talk about the case, but Cam isn't in the mood. Cam explains that she had a set of salt-and-pepper shakers that fit together. She gave one to Michelle before she left, and kept the other one. She told Michelle that whenever she looked at her half, Cam would be thinking about her. Brennan suggests that Cam take Michelle in now. She is an orphan. She needs someone to look after her. At Angela's office Brennan and Angela look through photographs from the hospital benefit. They rule out Dr. Bailey as the killer; her dress is white, and would have shown blood. Angela spots a snakeskin purse in the crowd. She magnifies the image. The purse has a tear. Angela moves through the photographs until they see the owner of the purse: Nancy Lauder. She's wearing a black dress.

At Roosevelt Hospital, Brennan, Booth, and Cam confront Nancy Lauder. She knows she's caught, and admits to burning the dress. Nancy was dating Welton when she found out he was sleeping with Bailey. She expects Cam to understand, but Cam can't empathize with what Nancy did. They're not the same. Cam, when confronted with the same situation, simply left him. At the Welton home, Cam tells Michelle that they caught the person who murdered her father. She then produces her half of the salt-and-pepper shaker set. Cam asks Michelle to consider living with her. Michelle is silent for a moment, and then runs out of the room. Cam, heartbroken, begins to leave, but moments later Michelle returns... with her shaker. She fits them together; the two shakers are little figurines, hugging each other. She runs to Cam, and they tearfully embrace. They're a family again.