The race is on. Dozens of costume-clad kids hurry through the haunted corn maze in search of the exit. One child, Matty, dressed as a Ewok, freaks as he twists and turns past skeletons, monsters and the grim reaper. Matty freezes at the sight of an all too real looking mummy hanging before him. A spider crawls out of the eye socket causing Matty to faint.
Booth and Brennan arrive at the maze soon after. Dr. Potoska, a local physician attempts to lead them to the mummy. The three of them wonder the maze aimlessly until Booth decides to muscle his way through the hay bails. They arrive at the mummy and after a quick assessment Brennan confirms it. These are actual human remains.
The mummy has been brought into the autopsy room where Cam, Zack, and Hodgins examine it. The squints are able to gather that the mummy is a female. The conversation turns to the annual Jeffersonian Halloween party, a mandatory event in which all employees must attend in costume. Zack will be going as the back end of a cow. Naomi from Paleontology will be his front. Hodgins will be attending as Edward John Smith, the captain of then Titanic.
On the mummy, Hodgins notices a coating of lacquer. He's found a label from The Free Church of America Thrift Store attached to the mummy.
Booth and Brennan are at the thrift store where they speak with Pastor Bill Jonas, the youth minister who runs the place. The church is preparing for its annual Halloween Hell House. An event showcasing what happens to those who abandon "the path of righteousness". As far as the case goes, Pastor Bill isn't much help. The clothes of the victim don't look familiar to him and none of the churches kids have gone missing.
Hodgins and Angela meet with Amber Kippler at the diner. Amber's a senior investigator with Doyley Private Investigations and she'll be taking over their case while Doyley is tending to a personal matter. Amber is very good at her business. She's tracked Angela's husband, Grayson, down. The man is in Florida. And Angela and Hodgins want her to head back down there to serve him with the divorce papers.
While driving, Booth and Brennan discuss the vehicles through which we all choose to believe. Brennan believes in what she can see, what she can hear. Booth believes in what he feels. Booth's cell rings. It's Cam:
Cam's in the lab. A very tired looking couple has been brought in. Cam tells Booth to hurry back and talk to them. The couple seems to think the mummy may be their missing daughter, even though she's only been missing for a week and the victim has been dead at least a year.
Booth and Brennan are back at Brennan's office where they speak with Don and Margie Shaw. Margie heard of the mummy discovery on the news and was convinced it had to be their daughter, Megan. Brennan assures them the body found at the maze was not their daughter. The Shaw's appear disappointed in this news, like they don't want to accept that it's not her.
Angela enters and gives Booth a rendering of the mummy girl. He shows the drawing to the Shaw's and it's confirmed. The mummy is not Megan. The Shaw's are broken and Brennan's wary of their backwards reaction. Cam calls with the news that another body's just been found at the Shoreline Amusement Park.
Booth and Brennan arrive at the amusement park. In front of the Dungeon of 1,000 Corpses haunted maze an EMT, Pete Geller, is tending to a breathless woman. The woman is a nurse and she saw a real human corpse in that maze, just beyond the killer clown. It's clear by Booth's reaction he no fan of clowns.
The partners enter the haunted maze and Booth freezes at the sight of the killer clown. Brennan thinks he may suffer from Coulrophobia, a fear of clowns. "It might explain why you shot that clown last year." Booth assures her he's okay. His phone rings. Cam is on the line:
From the lab, Cam tells Booth they've got an ID on the first maze victim. Her name is Stella Higgins, a fifteen year old who disappeared a year ago today. And she was last seen at the Shoreline Amusement Park. Booth hangs up and gets back to the task at hand. The two of them enter the torture dungeon where Brennan notices another all too real looking body amongst the pile of corpses.
Cam and Zack are in the lab where both mummified bodies are on display. Zack tells Cam that the dental records of the newest victim are not a match for the missing Megan Shaw. The cedar oil and lacquer on the body lead Cam to believe it's the same murderer. Zack doesn't want to jump to any conclusions just yet though. Cracked metacarpals and damaged fingers tell Zack that this victim may have been buried alive.
Angela enters with an ID on the second victim. A tattoo on the corpse is a perfect match for Judith Suzanne Evans, a missing sixteen year old. Judith's been missing for two years, to the day. She, just like Stella, disappeared from Shoreline Amusement Park. Hodgins enters with some news of his own. He's run some tests on the hair and skin found under the fingernails of Stella. It was her own. Stella pulled out her own hair. Cam notes her discovery of hundreds of tiny puncture marks all over Stella's body. And Hodgins adds that "the lacquer was infused with a number of particulates." One is a spore that he's going to investigate further.
Booth is outside of the Dungeon of 1,000 Corpses where he speaks with Dan Hauser, the manager of the haunted maze. A group of the costumed employees are gathered around and Booth recognizes one, Greg Liscombe. Greg plays the grim reaper and he was at the first crime scene as well. Booth wants to speak with him. This angers the heavily pierced zombie character, Lola. She wants Greg and everybody else to shut up without their lawyers present, ironically, she's the only one talking. And her mouth just landed her a new role, number one suspect in a murder investigation.
Back in the lab, Brennan, Cam, and Zack go over x-rays of Judith Evans. Judith's knees had tears, her fingers broken, her neck had compressions that indicate her head had been forced into a chin-to-chest position and her fingernails had been shredded. Cam wonders if Judith was buried alive.
Hodgins enters with more frightening news. He's found microscopic hairs on her body. Stella was bitten by spiders, tarantulas to be exact. The same wasn't true for Judith though. Hodgins didn't uncover any hairs on her but did come across plenty of other particulates, all of which point to internal combustion engines, or traffic. The only particulate still stumping Hodgins is steel dust. Cam goes to the computer where she has the tox results from the two bodies. High levels of ephedrine and theophylline found in both girls suggest highly accelerated heart rates. Cam ties it all in. The spider bites, drug induced panic and live burial makes Cam wonder "Is our murderer literally scaring girls to death?"
Booth is in his office with Sandy Evans, Judith's older sister. Sandy recounts, for Booth, the evening at the amusement park when Judith went missing. She says that Judith didn't want to go in the funhouse that night. She was claustrophobic. Judith, instead, waited outside as Sandy and their other friends went in. When they came out Judith was gone. Sandy remembers Greg, the grim reaper, being there that night. Greg had told Sandy that Judith had left with some guy.
Booth and Brennan have Greg Liscombe in the interrogation room. It turns out Greg is a registered sex offender. He's been arrested four times for exposing himself around teenage girls. And the fact that he was present on two separate occasions when remains of teenage girls were found is just too big a coincidence.
Booth wants to know about Megan Shaw and he starts slapping Greg around a bit. Brennan joins in. And Greg fesses up. It wasn't a guy that took the girls. It was Lola, the loudmouthed zombie girl. Lola is Greg's girlfriend and she would encourage him to fool around with these girls so she could barge in and catch them in the act. It would give Lola an excuse to smack the girls around a bit. An act that, Greg says "makes Lola hot."
Amber Kippler has returned from the remote Florida key were she has just spoke with Angela's husband. She tells Angela and Hodgins that Grayson Barasa won't sign off on the divorce. He's built a house for Angela and is still madly in love with her. Amber quotes Mr. Barasa as saying "Ever has it been that love does not know its own depth until the pain of separation." It's romantic but Angela still wants the divorce.
Booth and Brennan are walking and through the FBI headquarters when Agent Charlie catches up with them. Charlie has spoken with Megan Shaw's parents and learned that Megan has a fear of snakes. Booth wants Charlie to look into the matter, to call up every local pet shop and find out who's buying up snakes.
Back at the lab, Hodgins, dressed as the captain of the Titanic, and Cam, dressed as Catwoman, are looking over the microscopic spores. Brennan enters and questions Cam over her costume choice. Brennan isn't buying that Catwoman is a strong female super hero. Hodgins has discovered the mystery spore. It's Atronecium, from a Hawaiian orchid hybrid. This leads them to believe the victims were mummified in Hawaii.
Booth is back at the Dungeon of 1,000 Corpses where he is talking with Lola. Lola claims that all she does is rough up the girls. She leaves afterward, she swears. Booth isn't buying it and he arrests her.
Later on in the Lab, Booth dressed as a nerd/squint waits for Brennan outside the woman's washroom. Brennan is changing into her costume as Booth looks over the killer profile Dr. Sweets put together. The profile says their killer is definitely a male. It also says the killer works alone, throwing a chink into the Greg and Lola theory. Sweets' profile says the killer is probably unmarried and works a blue-collar job, probably something involving saving people. Brennan can't help but notice the many likenesses to Booth. She steps out of the woman's room dressed as Wonder Woman. Booth's jaw drops. Zack arrives dressed as the back end of a cow and the three of them head into Angela's office.
Angela, dressed as Cher, shows Brennan, Booth, Zack, and Cam a map on her computer. It's a map of three local pet stores that have all sold out of snakes within the past week, the last one selling out an hour ago. This tells the group that Megan Shaw is still alive. And since Greg and Lola are in custody it couldn't have been them.
Hodgins enters. He's trying to track down a location where the dead girls could have been exposed to the particulates he's found. Right now there's one hundred and twenty six possible locations. They are running out of time and Booth wants the squints to guess where it is. The squints don't guess and if they are going to work at their full capacity then all non-squints are going to have to leave them alone. Booth, Angela, and Cam exit the office and allow the squints to get to work.
Brennan and Hodgins hover over Zack as he works on Angela's computer. Based on what they already know the squints deduce the one hundred and twenty six locations down to a slimmer thirty one possible locations. Brennan factors in the bodies being mummified which requires a constant stream of dry air. This leads them to underground parking lots. Zack types it in and nothing comes up. The three of them start thinking about the steel dust. Hodgins comes up with train wheels, which they would find in the subway which would also contain a constant flow of dry air. And if they can find a Florist shop selling Hawaiian Orchids and situated above a subway, then they've got their location.
Booth and Brennan drive. Cam calls Brennan with the floral shop. Aloha Floral Supply fits the description and the costumed partners are on their way. Booth calls for back up.
Booth and Brennan arrive at the flower shop. They go around back and quickly come across a raised subway grate, just what they're looking for. Booth aims and shoots the lock off.
The partners climb down the grate into the underpass. With flashlights and guns drawn, Booth and Brennan advance to a subway access shaft. In one of the rooms, they find cedar-oil, lacquer, ephedrine and other drugs and then it hits Booth. He knows who the killer is, the EMT Pete. Pete has access to all those drugs and Pete had access to all those girls, showing up after Lola beats them.
A loud scream is heard and they trace it to a room with a padlocked door. Before Booth can shoot it, Brennan takes a shoot, firing her hand-cannon and sending a ricocheted bullet into Booth's leg. They open the door and dozens of snakes pour out. A freaked out Brennan hops on Booth's back and the two enter the room. Megan Shaw is in the corner surrounded by snakes and as the piggy-backing partners make their way to her, a clown brandishing a shotgun appears in the doorway. Before the clown can fire, Bones shoots, the recoil of the missed shot sends her flying of Booth's back. It's obvious that her weapon is way too big for her. So Booth swaps out his weapon for hers and gives chase to the fleeing killer clown. Brennan, with a more appropriate sized gun, stays back with Megan. The clown and the squint engage in a gunfight with Booth catching some shrapnel in the side. Pete knows Booth only has one shot left in his fifty caliber and as Pete takes cover behind, what he assumes is a solid doorway, Booth sends that last bullet through the doorway and into Pete, killing him.
Back at the lab, Angela meets again with Amber Kippler. Amber admits to attempting to seduce Grayson. She was testing Angela's husband. And what she discovered was that Grayson is deeply, deeply in love with Angela. Amber wants to set up a meeting between the husband and wife, to see if any sparks will reignite but all Angela wants is a divorce so she can be with the man she loves, Hodgins.
Angela leaves and Hodgins enters. He reminds Amber of her job which doesn't entail reuniting the married couple. Amber tells Hodgins to relax, she was only testing Angela, much in the way she was Grayson. Judging by Angela's unwavering stance it's clear Hodgins has nothing to worry about.
Booth and Brennan show up at the empty lab. They're dirty and bleeding and still in costume. Everybody is off at the party and the two flirt with the notion of showing up as a super couple, Wonder Woman and Clark Kent. They disregard the idea and playfully argue about Brennan shooting Booth and Booth dropping Brennan. Brennan feels for Booth for having to kill somebody, she knows he hates doing it, but he did it to save a girl. It needed to be done. The partners decide to skip the party and instead go get something to eat.