Booth and Bones arrive at a crime scene on the border of Oklahoma and Texas. They meet with both the OK and TX local police who are arguing over who's territory the crime scene is in. Bones asks to see the remains. She sees two skeletons and estimates the time of death about a month ago. Bones says the bones look like they are both females that were conjoined twins. Bones tells the officers that they will take over jurisdiction.
Vincent tells Camille and Bones that conjoined twins are rare. They wonder what exposed the bones. Angela tells the team that there was a sandstorm eight days ago. She says it should be easy to identify the remains since there are not many conjoined twins. Angela searches the database for missing conjoined twins.
Bones sees that the manner which the bodies were attached means that neither one could survive the death of the other. They figure the deaths were a result of murder/suicide. Hodgins comes back with a soil analysis and says there were traces of cotton and mites. He says the mites could only be found 100 miles away. He adds that he also found decomposed popcorn and Vincent says it must have been a traveling circus.
Sweets says wrapped naked bodies could mean there was sexual assault. Booth says he's going to talk to the circus. Sweets says circus folk are close knit and don't talk to outsiders. Booth and Bones ask how he knows. Sweets says he was adopted and went to a circus to find his birth mother, but no one would talk to him. Bones tells Booth that if they're going to talk to the circus, they're going to need an act.
Booth and Bones make a plan on their way to the circus. Booth says they need to get a mobile home to make their story more authentic. Bones says she thinks it might only take a night to talk to the girl's mother and find out what happened. Booth says he hopes not.
Booth and Bones meet with the twin's mother, Sandra Hicks and her husband/lawyer Dell. Booth asks about the lawsuits Sandra had against the circus. Dell lists the charges and Sandra says they stole her daughters. They say they last saw their daughters 4 months ago. Dell says Jenny wanted nothing to do with them and Sandra says they both wanted it. Dell says if Jenny wanted it, then it didn't matter what Julie wanted. Bones asks if they ever considered having them separated. Sandra says Julie and her thought it was too dangerous. Bones asks if the daughters disagreed on whether or not to be separated.
Booth and Bones talk to the twins doctor. He says he and Jenny thought the twins could safely be separated. He says it didn't matter what anyone thought, the twins had to come to an agreement before he could operate. He says the twins loved the circus and found ways to expand their act. He says they were just like any other sisters and had separate personalities.
Booth and Bones show up at the circus in disguise as Buck and Wanda. They talk to the ringleader and explain their knife throwing/high wire act. He asks them what their hook is and Booth says they are Russian. He asks to see their act and Booth successfully throws some knives, impressing Bones.
Booth and Bones return to their mobile home. They call Sweets and ask him what the circus lingo means. Sweets offers to email them a lexicon. Sweets tells Booth and Bones to not act like they are interested in any of them. He advises that Booth and Bones just pay attention to each other and let the circus members go to them. Booth gets and idea to shake the trailer to make it look like they are having sex. The ringleader and the midget stand outside and watch the trailer rock.
Booth walks into the tent and asks about Julie and Jenny. He says he used to work with them at another place. The ringleader say they don't work there anymore. He then pulls out a note from Julie and Jenny that says thanks for everything, but they're moving on. Bones says she's sure they'll run into them somewhere since there aren't many circuses anymore.
Back at headquarters, the team watches videos of the twins juggling. Vincent says the bones show a stab wound on the hand and Camille says they were juggling knives. Hodgins and Nigel then get into a spat over details. Angela walks in and says the note was written by a left handed person, but signed by both a right and left handed person. She says that the note is obviously fake.
Booth and Bones talk to the others about the girls. The ringleader says the clowns are the only ones who don't miss them. The detectives learn that the twins stole acts from the clowns to try to get more business for the circus. Someone then mentions that Julie had a boyfriend. Bones asks how that is possible if she had her sister attached to her all the time. Booth and Bones go back to the trailer and argue over the tidiness. They tell the team about the boyfriend and Hodgins asks how that can be possible. Bones asks Hodgins if he found something on one, but not the other. Hodgins says he found poly electrolyte polymers under Julie's fingernails, but not Jenny's. He says it was hair gel and suggests she got it under her nails by running it through her boyfriend's hair. Hodgins says the gel smelled like sandalwood. Booth says the doctor was wearing a ton of hair gel that smelled like sandalwood.
Booth tells Bones they need to talk to the doctor, but Bones says they can't because they have a show. Booth says they need to investigate a murder. Bones says they can't blow their cover. Camille then asks Bones to set up a web cam of their performance so that they can look for clues.
Vicnent tells Camille that the twins have identical head fractures, like their heads were cracked together. He says that he thinks it was the cause of death.
Bones and Booth talk to the doctor. Bones asks if she can run her fingers through his hair to prove he was having an affair with Julie. The doctor admits that he fell in love with Jenny first, but then fell for Julie and Jenny didn't like that. He says they kept the relationships secret. Booth arrests the doctor for suspicion of murder.
Booth and Bones ride a motorcycle back to the circus. Bones wants to talk about the act, but Booth says they're not doing the act. Bones answers Booth's phone and learns that the police can't hold the doctor for murder because his alibi checked out. Bones say that they need to work on their act.
Camille, Angela, and Vincent try to figure out how the sisters suffered their injuries. Angela suggests whiplash, a fall, and separate blows, but they are all ruled out. The detectives think the heads could have been knocked together. They figure that a soft object would have to have been used since there was no trauma on the other side of the heads. Angela suggests a clown prop could have been responsible.
Booth and Bones get into costume. They look through the clown props for a weapon, but are stopped by the clowns. The clowns get annoyed and say the stuff is not public property. Booth starts a fight, but the ringleader breaks it up. He angrily instructs everyone to start the show. Booth hits Bones in the eye, then says they can't go on since she is injured. Bones says the show must go on.
Booth and Bones watch as the show begins. Booth and Bones then take their turn at the stage. Booth tells Bones to be very still. The team hold their breath as they watch Booth hurl knives at the balloons around Bones's body. Booth successfully pops all the balloons and the crowd cheers. Bones then pulls out a prop apple and puts it on her head. Booth nervously throws the final knife, then the two take their bows. Bones then pulls out a fake nose and Booth nails it. Sweets tells the team that there is a sexual component to the act and Bones is showing incredible trust and submission. Booth and Bones finally leave the stage.
Booth and Bones watch the rest of the show. They see the strong man swing a prop mallet and launch a clown into the air. Booth and Bones then go to the strongman and ask him about the twins. He says he doesn't want to talk about them. Booth asks if he knows they're dead, then suggests he killed them. The strongman throws a net on the detectives and takes off.
Vincent tells Bones he found fractures on the legs and feet. Booth and Bones then argue about the act. Booth tells Bones the act is over and says they need to question the other performers.
Booth and Bones tell the ringleader that they are detectives looking for the killer of the twins. They say Magnum is their prime suspect. The others say Magnum would never had killed anyone, then they all remain silent. Bones realizes they don't have any definitive evidence. Bones then decides to try the highwire. Booth tries to stop her and says she has no depth perception because of her eyepatch. Booth then looks up and sees Bones walking across the wire. She complains that the rope hurts the bones in her feet. She then falls into the net. She lands and says she knows what happened. She says the twins leg fractures were from the highwire and they must have gotten the kissing fracture when they fell.
Magnum returns and tells the detectives he didn't kill the twins. Magnum says he buried them, but he loved them. Booth says they'll have to arrest him for tampering with a body. Booth asks why he wrapped the bodies in a sheet and says it is a sign of respect. The circus people then walk off silently. Booth and Bones wake up the next morning. They walk out of their trailer and see the circus is gone.