Who was the monster?
That was revealed on The X-Files Season 11 Episode 5 when Mulder and Scully investigated when a pair of teenage girls attacked one another.
The reason for the attack was that each believed the other to be a monster.
As the investigation progressed, the dynamic duo got closer to learning more details about their long-lost son, William.
Was he behind the attack?
Was he a monster?
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Paul Dailly is a staff writer for TV Fanatic. Follow him on Twitter.