|Lord of the Flies||Credits||Gallery|
When an amateur stunt performer is killed while performing a daring act for a local cable reality show, Scully, Doggett and Reyes discover that the culprit was apparently a swarm of killer flies hidden in the victim's brain.
A group of teenagers are filming one of their friends, "Captain Dare", doing stunts for their cable TV show, Dumbass. After a stunt fails and Dare falls out of a shopping cart, he is found dead with part of his head having collapsed. The local coroner calls in FBI Special Agents John Doggett and Monica Reyes, due to them being "specialists" in the unexplained. As Reyes examines the boy's body, flies erupt from his eye socket. The two immediately bring Dr. Scully in to examine the body. She discovers the caving-in of the head was not the result of an impact injury but because insects fed on the inside of Dare's head to such a degree that it simply collapsed.
At the local high school, Dare's friends are filming a memorial for their friend, much to the annoyance of Dare's girlfriend, Natalie. His friends catch Dylan Lokensgard – a misfit who is preyed upon because his mother is the principal – looking at Natalie, and harass him before being caught by his mother. Doggett and Reyes arrive at the school to talk to Dare's friend, David, who hosted the Dumbass show. During the questioning, blood-sucking insects attack David and their bite marks spell the word "Dumbass" into his backside. Scully later diagnosis the bites to have been caused by body lice, now extremely uncommon in the First World. While watching the recordings of the show, Doggett notices that Lokensgard was at each of the stunts and decides to question him. His mother becomes furious with the two agents, insisting they have no right to interrogate him when Dylan himself becomes covered in flies. Reyes starts to believe Dylan is behind the attack and called those flies on himself to draw suspicion off himself. She and Doggett take a tissue soaked with Dylan's sweat back for Scully to analyze, and it comes back heavy in insect pheromones.
Late that night, Natalie sneaks into Dylan's home; the two were once close friends but grew apart in high school. She tells him she never forgot about him and that, with Dare's death, she realizes how important he always was to her and to have someone around who understood her. They kiss but she pulls away, when something apparently cuts her mouth, and she leaves in tears. David and his friends, who believe Dylan had something to do with Dare's death, pull up moments later and drive off with him. During the drive, an insect-like protrusion comes out of his mouth and sprays webbing everywhere, causing the car to flip and crash. Doggett and Reyes find the crashed car, and the teenagers tell them that Dylan chewed his way out the back window, while Scully and an insect specialist search Dylan's home. Scully leaves to help Reyes find the teenager while the specialist stays behind, and is attacked by Dylan's mother. Reyes tracks down Natalie, whom they saw talking to Dylan earlier in the day, but Dylan arrives and cocoons Reyes. Dylan's mother approaches him and tells him he is not like other kids and never will be, and that what's happening to him is what she was trying to explain to him earlier. Doggett arrives at Natalie's home and finds Reyes cocooned alive. Scully goes back to the Lokensgard house after losing contact with the entomologist and finds Natalie sitting frozen in fear and crying on a chair in the living room, but Dylan and his mother are nowhere to be found. A search of the Lokensgard home turns up the insect specialist, who was cocooned but survived, as well as the bodies of several other people, including Dylan's father, who supposedly ran off, years earlier.
Dylan and his mother drive away, with Dylan looking visibly depressed. Natalie looks out her window to see fireflies forming the words "I Love You," while Scully overtones that, sometimes, the heart wants what the heart wants.
- The reality show in this episode is called Dumbass, a fictitious relative of MTV's Jackass. In both series, the cast perform dangerous stunts.
- In this episode, Scully makes it clear she dislikes flirtatious entomologist Dr. Rocky Bronzino. In the Season 3 insect-themed episode "War of the Coprophages", she makes it clear she dislikes flirtatious entomologist Bambi Berenbaum.
- The posters on Natalie's wall reference the bands Radiohead, Garbage and Fear Factory, among others. The posters on Dylan's wall are from the work and life of Syd Barrett, a founding member of Pink Floyd as well as fine artist, who spent the final forty years of his life in solitude. The song Dylan quotes is Barrett's Opel.
- There is a song called "Nathalie and the Fireflies" on the 2002 album The Neonai, by the band Lake of Tears.
- This episode stars Aaron Paul, who later worked with this episode's writer Thomas Schnauz, and the show's producer Vince Gilligan, on Breaking Bad.
- Gillian Anderson as Special Agent Dana Scully
- Robert Patrick as Special Agent John Doggett
- Annabeth Gish as Special Agent Monica Reyes