DALE MCGILLIARD and ELLIE SPILLER marry on a hot air balloon, drifting above a seaside cliff. Their friends and family stand on the cliff, watching as Dale and Ellie become husband and wife. The crowd cheers as the couple kisses and bungee jumps off the balloon into the gorge below. However, their bliss is short lived. A decaying corpse waits for them at the bottom of the gorge. Dale and Ellie bounce over the body, screaming in horror.
BOOTH and BRENNAN arrive on scene. Booth believes the victim died as the result of a bungee accident, but Brennan dismisses this theory. "This compound tibial fracture; if he was still alive when he fell, the bone should have bled." The victim was thrown over the cliff post-mortem. They are looking for a murderer.
At the lab, VINCENT NIGEL-MURRAY assists CAM in the autopsy room. Like Booth, he doesn't understand the appeal of bungee jumping. ANGELA and Brennan enter. The victim was undergoing dental restoration. Angela volunteers to send pictures to Booth. Maybe they can identify the victim through a local dentist. Further examination reveals that the victim was punched in the nose before he died. Hodgins arrives with time of death: two to five days ago. He admits that his findings are strange, because the body shows a higher rate of decomposition, but insect activity doesn't lie. Vincent notices that the victim's flesh is moving. Cam cuts into the skin and foam oozes from her incision. Cam presses the emergency alert button as the Squints cover the mouths to avoid breathing potential toxins. The Jeffersonian is in lockdown.
At the lab, the body is encased in an isolation table. Cam insists that no one touch the body until they identify the mysterious foam. However, Brennan would like to examine the bones. Hodgins would like more samples. Cam would like everyone to leave her alone as she collects the foam for testing. Angela enters with a name: ALEX NEWCOMB, 33. The FBI found his dentist. Alex's brother is listed as the emergency contact. He works at Jungle Jim's Pre-Owned Paradise. Cam sends Brennan off to work with Booth instead of hovering over her.
Booth and Brennan arrive at Jungle Jim's Pre-Owned Paradise. MAUREEN PEROT stops the pair, trying to sell them a car. After all, she is the "Bwana of the Month." Booth badges her and she points to CHET NEWCOMB. His wife, VANESSA NEWCOMB, gives Chet his medication: desmopressin. Brennan realizes Chet has kidney problems but Chet downplays his condition in hopes of making a sale. Booth explains he is with the FBI. Vanessa, a seamstress, offers to leave them in private. She has a client waiting for a dress anyway. Brennan encourages her to stay. Chet may need comforting when he hears that his brother has been murdered. Chet is distraught. He explains that Alex worked for Jungle Jim but he quit a few weeks ago and went to the Criterion Car Dealership across the street. Alex had quite the fight with Jungle Jim when he left.
Still at the lab, Vincent uses gloves to examine the victim. He notices fractures that suggest a fall, but it is not the cause of death. Cam is frustrated in her search to identify the foam. She runs test after test. Suddenly, the foam reappears. Vincent alerts Cam that the foam is coming from inside the bones themselves.
At the FBI, Booth interrogates KEVIN HOWARD, a.k.a. Lemon Guy. Howard tells Booth that the brakes on the car he bought failed as he was driving from the lot. His four-year-old son was injured. Howard is still emotional over the incident, but he didn't kill Alex. He would never leave his son without a father.
SWEETS and Brennan watch from the Observation Room. Brennan wonders about Booth's techniques during an interrogation. Sweets explains that he has to manipulate people to get answers. In fact, Sweets used to teach those same techniques to car salesmen to earn money for graduate school. He's not exactly proud of it. Brennan makes a decision. She wants Sweets to teach her how to interrogate suspects. "In the spirit of scientific inquiry, I'd like to see if what you say about psychology is true."
At the lab, Vincent works as quickly as he can, trying to find the murderer before they lose the bones. Hodgins enters, having analyzed particulates from the clothing. There was "lust dust" on the victim's pants. He had a lap dance before he died.
Brennan accompanies Booth to the Imperial Showgirls Strip Club, eager to observe his next interrogation. After asking around, Booth finds STRAWBERRY LUST, the dancer who wears lust dust. She begins to give Booth a lap dance. Booth is momentarily tongue-tied. He regains his composure enough to ask his questions. Alex Newcomb was one of her regular clients. She danced for him on Thursday, but he got into a fight and was thrown out. Who with? His co-worker: Buddy.
In Brennan's Office, Brennan begins her training with Sweets. "We'll start with a simple exercise to recognize emotions from facial expressions. Then I'll give you skills to deal with those emotions." Brennan fails to identify confusion. Sweets instructs that the proper response to confusion is empathy to the person's situation. She correctly identifies anger but isn't sure how to respond. Sweets is a bit frustrated, but assures Brennan that she will get the hang of it.
In the Ookey Room, Hodgins notices that the skull is melting. Vincent hurriedly prepares a C-Ring magnifier to enlarge their view of the body. However, when he plugs it in, it shorts out. The lab once again goes into lockdown, as flames begin to engulf the body.
As the doors at the lab unlock, Vincent and Hodgins have a lot of explaining to do. Brennan and Cam listen to their account of events. Brennan has a realization. "If the light was the ignition source, that suggests the body was emitting some kind of gas." Cam deduces that it is hydrogen gas. Hodgins mourns the loss of his eyebrows to the fire.
At Criterion Car Dealership, Booth inspects an Audi R8. He wants to take a test drive. Buddy agrees, looking to make a sale. On the test drive, Booth drives so fast that Buddy fears for his life and for the car. He spills everything. He punched Alex Newcomb in the nose because Alex stole his client. They were both thrown out of the strip club. Alex got into a cab and told the driver to take him to Jungle Jim's. He was going to get his old job back. Booth ends his joy ride. Buddy is thankful when Booth gets out of the car.
At the FBI, Booth calls Brennan to tell her that Alex wanted his old job back. He felt guilty for leaving his brother to fend for himself. After the phone call, Vincent gives Brennan an update. However, everything he wants to show her has dissolved. The Squints realize that the bones are dissolving faster than the body because the bones contain calcium. Hodgins concludes that hydrofluoric acid must be destroying the bones. "Antacid contains magnesium hydroxide. We cover the hydrofluoric acid in enough magnesium, it'll stop attacking the bones." He sprinkles antacid over the bones. The foam begins to disappear. Before the Squints can celebrate, a hard white shell forms on the body. The lab goes into lockdown. Not again!
At the FBI, Brennan begs Booth for a shot at interrogating Maureen Perot alone. Booth relents. He and Sweets observe in the Observation Room, ready for an interesting display. In the Interrogation Room, Brennan asks Maureen her questions. Brennan doesn't pick up on Maureen's jokes and the two of them don't quite understand each other. Booth coaches her through an earpiece until they have what they need: Alex was helping Chet increase his sales. That is what caused Alex to drop to Bwana Number Three.
At the lab, Vincent tells Cam he may have a cause of death. From the X-rays and MRI scans, there appears to be a mark left by the murder weapon. The only way to know for sure is to crack open the body. Hodgins arrives, confirming that the victim was covered in highly concentrated hydrofluoric acid. He also found fecal matter on the victim's shoes. It belongs to a Capuchin monkey, just like the one Jungle Jim has.
An FBI Forensic Team combs Jungle Jim's. Jungle Jim is not pleased, but they have a warrant. It's not long before the techs discover blood. In the garage, Booth and Brennan see traces of blood on the floor. Brennan notices a barrel of Gleam-O, a tire cleaner. It is hydrofluoric acid. Someone killed Alex in this garage and doused his body in Gleam-O.
Brennan, Booth and Cam discuss the case at the Founding Fathers Bar. The killer probably doused the body in acid, thinking it would dissolve instantly. When that didn't happen, they had to get rid of the body some other way. Hence, it went into the gorge. The only employee at Jungle Jim's that night was Jungle Jim. However, there is no evidence to suggest that Jungle Jim used his car to dump the body.
At the lab, Cam and Vincent are unable to determine a murder weapon from the X-rays. Frustrated, Cam grabs a club and moves the crack open the body. Vincent stops her. This could destroy the evidence, not free it. Cam convinces him there is no alternative as Angela appears. No one thought to ask her but she has a solution.
Brennan joins Angela in her office where she is virtually re-growing the bones. While Angela works, Brennan laments her attempt to question Maureen. Even after all she learned from Sweets, she couldn't interrogate like Booth. Angela tells Brennan she can't learn what Booth can do. He is a natural. He has instincts. Booth lets Brennan be the smart one. She should let him be the one with the people skills. Brennan thinks about this as Angela shows her the virtual skeleton. Her rendering reveals that the murder weapon was a pair of tailor shears.
At Jungle Jim's, Booth and Brennan search Vanessa Newcomb's van. They find a large pair of tailor shears. Vanessa breaks down. She slept with Jungle Jim so Chet could keep his job. Alex found out what she had done when he turned up to get his job back. He was going to tell Chet so she killed him. It was all for her husband.
At the Founding Fathers Bar, Booth tries to make Brennan feel better about her interrogation. Brennan admits that Booth is better than she is with people. Booth is touched that she acknowledged his skill. He brings her outside to show her the Audi R8 Buddy let him borrow. Brennan wants to drive. Booth reluctantly agrees to let her go once around the block. Brennan doesn't get that far. She immediately causes a traffic jam. Booth gets out of the Audi and into a cab. Brennan can handle this one on her own.