SANTA CLAUS is coming to...rob Capital Mutual Bank? The teller quickly hands over the cash when she sees that Santa is outfitted with a bomb.
MAX KEENAN drags a Christmas tree into Brennan's apartment. BRENNAN informs him she is volunteering in El Salvador for the holiday. Max does not want to be alone at Christmas. Brennan agrees to stay if Max will introduce her to one of her blood relatives.
Booth responds to the call for help at the bank. He comes face to face with Santa as he runs out of the bank, clutching a red sack filled with money. Santa looks distraught. "I just answered the call." There is a crackle and Santa EXPLODES!
EMTs load a CAB DRIVER into an ambulance as CAM and Brennan ensure Booth is unharmed. Booth passes the examination and begins to question GEORGIA HARTMEYER. She witnessed the blast and, as a result, is covered in evidence...human remains. Cam explains that Georgia must accompany them back to the lab.
HODGINS collects pieces from the bomb with magnetized gloves. Booth spies an oily puddle on the ground. According to Hodgins, it indicates the bomb was homemade. Booth decides to go home for a shower, but Brennan stops him. A chunk of spinous process clings to the back of his jacket. Booth is evidence.
Brennan carefully removes remains from Booth, proceeding to undress her partner. "There may be particulates." She removes his tie and unbuttons his shirt. Since Rebecca has Parker for the holiday, Brennan invites Booth to Christmas dinner at her apartment. Cam enters as Brennan slides off Booth's pants. Cam explains to the embarrassed partners that the bomber had propranolol in his blood stream. Booth is familiar with the substance. He knew snipers that took it to steady their nerves. What's more, Hodgins swabbed a nostril fragment and discovered limonene, a citrus fruit derivative.
Still in his boxers, Booth questions Georgia Hartmeyer. She is being uncomfortably cleaned by DAISY. Georgia explains that she was waiting for the bus when the explosion occurred. She just wants to go home. Hodgins arrives with a computer chip. He has determined that the bomb was detonated via a two-way radio, set to 27.4 Megahertz. Santa didn't do it himself. Perhaps he had a partner.
In Angela's Office, ANGELA watches as Booth tunes a scanner to 27.4 Megahertz. A voice comes alive. "Burn them like they burned us!" Booth realizes that he heard this voice just before Santa exploded. They need to find the source of the transmission. This man could have detonated the bomb.
Elsewhere, Daisy reconstructs the skull. SWEETS arrives to discuss holiday plans. Daisy won't celebrate Christmas in December because Jesus was born in March. On December 25th, they should simply stay in bed all day. Cam wonders if the couple was invited to Brennan's Christmas dinner. Daisy explains that they can't attend until March.
Inside an FCC Frequency Scanner Van, Booth and Brennan close in on the radio signal. They come to a house with a radio antenna on the roof. The driver pulls over. This is it. Booth cleverly pulls down the antenna, prompting OWEN THIEL to come outside. Booth grabs Owen and forces him to the ground. Santa's helper has the right to remain silent.
At the FBI, Owen Thiel waives his right to a lawyer. He knows his rights better than some "pawn of the system." Thiel spent time in the military. Booth knows he would have learned about explosives in basic training. Is that why his radio frequency detonated a bomb? Owen Thiel thinks it is a coincidence.
At the Diner, Brennan and Max sit with MARGARET WHITESELL, Brennan's second cousin. She likes to "get away" from her family for Christmas. She also likes to quote Benjamin Franklin a lot. Margaret rubs Brennan the wrong way. Margaret thinks Brennan is a know-it-all. Brennan decides to go to El Salvador for Christmas.
Daisy brings the reconstructed skull to Angela. She applies clay to the skull and carefully crafts the face of the bomber. Now they have to get this image to the media.
In the Autopsy Room, MICHELLE finds Cam surrounded by Christmas decorations. She wants the holiday to be special but Michelle has her own ideas. She wants to go to Hawaii with her friend, Paris. If she stays in DC, she'll just be depressed. Cam tells Michelle she can take the trip, even though she is less than happy about it.
Hodgins leads Cam into the Bone Room. He explains that the explosive residue was composed of ammonium nitrate, fuel oil, naptha, detergent and antimony sulfide. Still, this information can't identify the bomber. Daisy has the skeleton mostly reconstructed but they are missing pieces of manubrium. Cam realizes they never examined the Cab Driver.
At the Founding Fathers Bar, Booth tells Brennan he will be joining her for Christmas dinner. Brennan has to cancel. She didn't like her cousin so she won't be around for the holidays. Booth encourages Brennan to give Margaret another chance. Family usually gets under your skin. Brennan realizes that Booth and Jared are often at odds so maybe Booth is right. Booth gets a call. Someone recognized the sketch on the news.
At the FBI, Booth and Brennan speak with ABBY CHEVALEER. Her son is HOLDEN CHEVALEER. He is an exterminator. Brennan realizes that many of the substances in the bomb are used in that profession, such as naptha and limonene. Abby insists her son is a good boy. Why does the FBI need information about him? Can Abby speak with him? Booth's expression reveals the terrible truth.
Meanwhile, Cam has been in touch with the hospital. It seems the Cab Driver tried to shield himself from the explosion, and shrapnel was lodged in his face and hands. Daisy is adding the missing pieces to the skeleton. Hodgins will figure out the bomb so Angela can recreate the explosion.
When Hodgins and Daisy look at the missing manubrium, he can tell that the base of a small light bulb was used as the initiator. Daisy has also discovered a wire fragment.
At Brennan's Apartment, Brennan tells Margaret she is now staying in DC for Christmas. Booth arrives to inform Brennan that the Explosives Unit found nothing suspicious at Holden's house. Brennan introduces him to Margaret. When Booth leaves, Margaret says she doesn't find Booth attractive. What is with wrong with this woman?
At the FBI, Own Thiel waits for Booth. He was hoping to speak to Abby Chevaleer. He wants to make amends. Booth does not want anything to do with Owen Theil. He shows Thiel out. Cam and Hodgins contact Booth with news: the details of the bomb match the signature of a man names Malaki Wallace. He robbed a Western Union in the 90's but has been dormant since he was released from prison.
MALAKI WALLACE insists that he is out of the bombing business. He has an alibi for the last 48 hours as well: tending to the clogged sewage line at his apartment complex. Wallace explains that anyone can make his bombs: the recipe is on his website.
Daisy shows Brennan a puncture mark on the right articular capsule. Brennan believes this is where the propranolol was injected. Daisy shows her evidence that proves the victim was right handed. Therefore, he couldn't have injected himself in the right arm.
Hodgins and Brennan confer with Booth. Not only did Holden not inject himself, he didn't put the bomb on either. Hodgins discovered the remnants of a bike lock. Holden was locked into the bomb. Booth now knows what Holden meant when he "answered the call." He was an exterminator. He answered a service call and the customer made him rob a bank.
Cam catches Hodgins constructing a bomb in the Ookey Room. She DOES NOT want explosives in the lab. Hodgins assures her it is perfectly safe. Cam notices that his fingertips and fingernails are black. Why? Hodgins explains that the antimony sulfide caused the color change. Cam immediately rushes to pull the evidence trays.
Angela and Hodgins assist Cam in retrieving Georgia Hartmeyer's fingernail. The fingernail is black. Hodgins confirms the substance is antimony sulfide. It could only be there if Georgia helped assemble the bomb.
Georgia Hartmeyer sits in the Interrogation Room as Booth and Brennan hit her with questions. Why was she waiting for the bus at the bank when she lives on the other side of town? She was fired three months ago, so she wasn't going to work. She has never made a purchase in the area so she wasn't shopping. What was she doing? Despite the evidence, Georgia insists she is innocent.
In Angela's Office, Angela presents her reconstruction of the explosion. There is a problem: the Cab Driver covered his face too early. He shouldn't have had time to react that quickly. He knew the explosion was going to happen. The FCC's Frequency Allocation Chart shows that the Cab Driver used the frequency 27.41 Megahertz. Owen Theil broadcast on 27.4 Megahertz, and inadvertently beat the Cab Driver to the explosion.
Booth tells Brennan that Georgia and the Cab Driver turned on each other. They met at a Debt Counseling Seminar and picked Holden randomly from the phonebook. Brennan shares that Abby is burying Holden on Christmas morning all by herself. Brennan thinks they should attend. No one should be alone at Christmas.
Cam is driving Michelle to the airport when she pulls to the side of the road. She doesn't want Michelle to go to Hawaii. Cam explains that there is no Christmas without Michelle. She is family. Michelle hugs Cam. She loves her and will stay.
Owen Thiel broadcasts from his house as Booth and Brennan join Abby Chevaleer at the cemetery. Abby is touched and thankful. Thiel tells his listeners that he is deeply sorry for what happened to Holden. This is his last broadcast. His listeners should remember one thing: "Peace on earth." Angela, Hodgins, Daisy, Sweets, Cam and Michelle file in behind Booth and Brennan. Holden now has a proper sendoff.
Everyone gathers around the dinner table at Brennan's Apartment. Brennan tries unsuccessfully to give a toast so Booth steps in. "To family, friends, lovers, family and food." Brennan doesn't want anyone to pray so they all hold hands for a moment of silence. Booth steals a glance at his partner while the snow gently falls outside.