While camping, a boy stumbles across a decaying, maggot-infested body. Booth, Brennan, and Cam show up at the crime scene. The body is meaty, and Bones wants to know why she was pulled along. A quick-thinking Cam notes that the feet have been hacked off, suggesting bone trauma.
Back at the lab, Brennan and Cam observe the body. He's been dead four days. His hands were tied before death and his feet hacked off after death. Hodgins enters with news about the ongoing hunt for Angela's first husband. A therapist wants to hypnotize Angela into remembering anything about her husband that could possibly help in hunting him down. Hodgins also has news on the body: the shiny substance on the victim's nose and mouth is a specialized sunscreen used on horses. Searching through the stomach, Cam finds raw oats and molasses...horse food. Booth has the victim's name: Ed Milner, or Mr. Ed.
Booth speaks with Alice Milner, the widow of the victim. According to Alice, Ed was away on business, nowhere near the woods where his body was found. Booth asks Alice if Ed had a fascination with horses. Alice says "no" and is confused by the question.
Brennan is hard at work in her office when Booth enters. She's been doing research: The hooves of dead champion thoroughbreds are detached from the corpse and buried separately, since they represent power and need their own resting place. She thinks that the removal of the victim's feet was ritualistic. Booth has tracked down the victim's last credit card purchase - The Ambassadora lodge.
Booth and Brennan arrive at the Ambassadora. They question the discreet owner of the Bed and Breakfast, a man named Lucky. With a little pressure applied, Lucky spills the beans. His lodge is a place where people can go to experience pony play, a form of sexual role-playing involving "ponies" and "riders". Ed Milner (Mr. Ed) was a pony. Booth and Brennan want a word with Mr. Ed's rider.
Booth and Brennan walk and talk with Annie Oakley, Mr. Ed's rider. She was in love with Mr. Ed, in "the way a young girl feels for her first pony." Annie thinks they need to speak with Ed's wife, who, she claims, showed up at the Ambassadora the night before Ed died. Apparently, Alice Milner caught the two role-players together, in character.
Booth and Bones drive while discussing pony play and it's clear they have opposing viewpoints on the fetish. With Booth stating that "maybe if Ed lived like a man, he wouldn't have died like a horse."
Booth and Brennan have brought Alice Milner into the interrogation room. Alice admits to knowing more than she had originally let on. Alice tells Booth and Brennan that she got a call from a man with an accent. The man told Alice that Ed was with another woman and the mystery man knew where Alice could find the two together. Alice showed up at the Ambassadora that same evening and walked in on Mr. Ed with Annie Oakley. Alice swears that after discovering the pony-players she left and immediately contacted a divorce attorney. Booth's not buying it.
Brennan doesn't think Alice Milner did it. The ritual of removing and burying the feet points to the pony-play culture. They need to get hold of that mystery caller.
In the lab, Zack and Hodgins work on determining the murder weapon and a cantaloupe may be able to help them to do that.
Booth and Brennan are back at the Ambassadora. They're looking for leads on the caller. They know he has an accent and soon meet Thor, from England. Thor, real name Calvin Johnson, admits to calling Ed's wife but claims that he'd never commit murder.
Angela's combing her office for a wedding picture when Hodgins enters. She needs to bring a photo to the hypnotist but isn't having much luck.
Back in the lab, Zack's got the murder weapon; a hoof knife. It's a weapon used to slaughter horses with a single blow to the forehead. This is exactly the way Mr. Ed was killed.
In the lab, Hodgins tells Cam about the specialized twine used to tie together Ed's hands. It's a patented product only sold by one company. They should be able to get a list of customers directly from that company. They'll then be able to cross-reference the customers with the pony-players.
Angela is in her office trying to meditate when Brennan enters. The hypnotism didn't take because Angela wasn't relaxed enough. Brennan points out the anxiety indicators present in Angela. Angela tries to convince Brennan that she's not anxious because sub-consciously she doesn't want to find her husband's real name. Brennan surmises that a "real name" will humanize him, diminishing that "untouchable fantasy figure image" she has created for herself.
Booth has Lucky in the interrogation room. The twine used to tie Ed's hands was traced back to the Ambassadora. They also now know Lucky used to be married to Annie Oakley. Lucky admits to owning a hoof knife like the one used to kill Ed but claims that his was stolen four days ago. He thinks Tom Mularz -- a local butcher/former pony-player stole it.
In the lab, Hodgins and Zack have, separately, come to the same conclusion. The hoof knife used to kill Mr. Ed was also used to hack off his feet.
Booth and Brennan arrive at the Butcher shop to question Tom Mularz. Mularz takes off but doesn't get far before Booth slams him into a wall and cuffs him.
Booth and Brennan interrogate Mularz. Mularz is an advocate for the human consumption of horse meat. He shared his believes at the convention and drew ire from the others. He fesses up to breaking into Lucky's car but it wasn't to steal the knife. He took back his horse-meat brochures, which Lucky had confiscated. Mularz has an alibi.
Angela is back in the therapist's office, with the correct levels of relaxation and ready to be hypnotized.
In the lab, Brennan has come to the conclusion that the victim's eyes weren't eaten by maggots, as initially thought, they were carefully gouged out. She shares the information with Cam. This information suggests that whoever killed Ed is skilled with a medical instrument. They recall that Annie Oakley is a doctor.
Back in the therapist's office, Angela is going under. Her therapist, Dr. Jasper, has mentally placed Angela on the island, in front of a door that leads to her husband. Angela is told to open the door and greet her man by his proper name. Upon opening the door, Angela is greeted by a giant buzzing wasp.
Bones and Booth are back at the Ambassadora were they've got their killer, Annie Oakley. She's defiant at first but finally breaks down. She left her husband and Thor for Ed, but Ed wasn't willing to leave his wife for Annie. She confesses.
Back at the lab, Hodgins has just finished researching what a wasp means in dream theory; it means anger. Angela enters with a book that could help. On the cover is a giant wasp. Inside is a picture of Angela and Birimbau. And even better it's got his name on it. Angela is legally married to a'Grayson Barasa'.
At the diner, Brennan and Booth discuss the merits vegetarianism. Then, they discuss their views on pony-play. Booth reveals himself to be a romantic, believing that fetishes are a poor substitute for love. For once, Brennan agrees with him.