When Mulder and Scully are in the library, if you look at the newspaper report, above the story of Howard Graves' suicide there is an article about a killer who extracts his victim's livers and escapes from impossible locations. This is a reference to Eugene Tooms from Squeeze (1993).
This episode features a recurring motif in the series where Mulder dashes into a situation to witness a paranormal happening while Scully is somehow delayed and misses it. (In this instance, she's having trouble with her seat-belt.) This is a writer's trick to help preserve the trademark Scully scepticism.
Four industrial fans generating winds of up to 100mph were used to create the climactic office hurricane. The scene was filmed late at night and the noise generated by the fans was so loud, that an infuriated neighbor started complaining about it.
This episode was partly inspired by the horror film The Entity (1982). The film starred Barbara Hershey, who later played Erika Price in Season Eleven.
When Mulder and Scully are in the car park, and Howard Graves' car parking space is being renamed, the name being painted on is Tom Braidwood - who is the actor who plays Frohike and is also an Assistant Director on the series.