In the town of
Gibsonton, Florida, two brothers are playing in their outdoor swimming pool. A mysterious figure approaches them from the woods and jumps into the pool without their noticing. As the brothers play, they notice something is wrong. The figure emerges from the water; it's revealed to be the boys' father, a
freak show act named the "Alligator Man", who scares his sons for fun. After the boys leave the pool for bed, their father stays behind to swim. Another mysterious figure approaches the pool from the woods. It attacks and kills the "Alligator Man" in his pool. Agents
Fox Mulder (
David Duchovny) and
Dana Scully (
Gillian Anderson) travel to Gibsonton to investigate a 28-year series of attacks by an unknown assailant in a community of former freak show performers. They attend the funeral of the "Alligator Man" (who suffered from
ichthyosis). Among the people they meet afterwards are "self-made freaks" Dr. Blockhead (
Jim Rose) and his "
geek" sidekick, The Conundrum (
The Enigma), who will eat anything but says nothing. The agents also meet former performer Jim Jim, the "
Dogface Boy", who later became the local sheriff after his face went through
hair loss. Mulder and Scully stay at the
Gulf Breeze trailer court. Here, they meet the distrustful manager Mr. Nutt (
Michael J. Anderson), a
dwarf, and Lanny (
Vincent Schiavelli), an alcoholic with an underdeveloped
conjoined twin named Leonard. The agents hear a story about the legendary
Fiji mermaid, a common sideshow act in the 19th century that generally turned out to be a monkey with a fish tail attached — the "
humbug" referred to by the episode's title. Despite Scully's usual skepticism, Mulder is intrigued because of what look like
simian tracks left by the mystery attacker. One night, Mr. Nutt is fatally attacked by the creature, who the agents eventually discover is Lanny's twin, Leonard, who is able to detach himself from Lanny's body. According to Lanny, Leonard attacks people and attempts to burrow into them because he is looking for a new brother to replace Lanny, who is dying from
liver failure. Lanny voluntarily locks himself in the local jail in an effort to keep Leonard from escaping, but dies during the night. Leonard slips through the bars on the cell window and flees. Mulder and Scully try to capture Leonard, who goes inside a
funhouse, but he seemingly manages to get away. Upon leaving the funhouse, the agents find The Conundrum lying on the ground, rubbing his stomach, apparently having been attacked by Leonard. As Dr. Blockhead prepares to leave town with The Conundrum the following morning, he comments to Scully that with modern science eradicating genetic anomalies, it will be up to self-made freaks like him to remind people that "nature abhors normality." The Conundrum looks unwell and Mulder asks what the matter is. The Conundrum — in his only line of the episode — replies, "Probably something I ate." As Dr. Blockhead drives away with The Conundrum, Mulder and Scully turn to each other with confused and somewhat shocked expressions. ==Production==