One night, Mr. Nutt is fatally attacked by a creature. The agents eventually discover that the attacker 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 due to years of alcohol abuse. Lanny voluntarily locks himself in the local jail in an effort to keep Leonard from escaping, but dies during the night, and Leonard is able to slip through the bars on the cell window and flee. Mulder and Scully try to capture Leonard, who goes inside a funhouse, but he manages to get away. Upon leaving the funhouse, they 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.