Plot summary
In his room in Fairhope, Pennsylvania, young boy Tommy Conlon (Gavin Fink) believes he sees a monster reflected in his mirror. He calls for his dad, Jeffrey Conlon (Scott Paulin), who looks under the bed and sees a crawling bug-like creature. He lies to his son, telling him that he sees nothing, and tells Tommy to go back to sleep. Tommy sees the creature again and calls for his dad; Jeffrey holds the door shut as Tommy bangs on the door.
Meanwhile, Agent Leyla Harrison (Jolie Jenkins) tells Dana Scully (Gillian Anderson) about a woman who stabbed herself repeatedly. Harrison insists that the case is an X-File and that the woman was killed by monsters that her son Tommy saw. She also believes that the monster killed the family cat, Spanky. Scully dismisses Harrison's claims, so Harrison dupes John Doggett (Robert Patrick) and Monica Reyes (Annabeth Gish) into investigating.
Doggett, Reyes, and Harrison arrive at the Conlon residence in Fairhope, Pennsylvania. The agents talk to Tommy and conclude that something is going on. They soon discover that their car will not start. Back at her apartment, Scully is visited by Gabe Rotter (Brian Poth), a potential suitor of Harrison's. He presents Scully with the corpse of Spanky. Scully does an ad hoc necropsy and concludes that the cat bit its stomach open to try to get something out. She also discovers a cavity, where it appears something had lived inside the cat.
Doggett, Reyes, and Harrison camp out at the Conlon's house and soon witness the monsters: large, silverfish -like creatures that multiply when shot by Doggett. Alerted by Scully, the local sheriff (Steve Ryan) arrives, but a scuffle ensues. The sheriff draws a gun, and Doggett gut punches him, only to have his hand go completely through the man's stomach. Upon investigation, Reyes is unable to find any organs in the man's body. Tommy shows Reyes the pictures he has been drawing. They include the sheriff with a gun, insect creatures, and Reyes with an insect creature bursting from her body. Reyes asks Tommy why he would imagine such things, and Tommy replies because he is very scared.
Suddenly, the sheriff's body disappears, and Reyes doubles over in pain. Doggett and Harrison pull up her shirt to reveal movement in her abdomen, as if something is trying to get out. Harrison then begins to bleed from her eyes. Doggett approaches Tommy, orders him to stop, and follows him down the hall when he fails to stop. Doggett follows Tommy into a room, but plummets into a blackened abyss where he is attacked by the insects. However, due to Doggett's skepticism, he is able to fight off the illusion.
Because he does not believe they are real, they cease to be real. Doggett explains to Jeffrey that all of the creatures are imaginary and are produced by Tommy's imagination. This includes the bugs, the "sheriff" who had no organs, and Reyes's and Harrison's ailments. Jeffrey's wife and their cat Spanky killed themselves trying to remove the insect creatures, believing they were real.
Doggett tricks and subdues Tommy by pretending to set the house on fire. He pours a gas canister filled with water over the floor and furniture, acting as though it is gasoline. Because Tommy believes it to be real, when Doggett lights a match, he sees an inferno surrounding him in the living room. Tommy passes out in fear. Tommy is eventually transported to a psychiatric ward where his imagination is suppressed by watching a wall of television screens.
Credits
Adapted from Wikipedia contributors, Scary Monsters (The X-Files). Paragraphs and formatting adjusted; illustrations, reference markers, block quotations and non-story material omitted.