This is the first time that Scully fires her gun.
The climax is the scene in which Scully nearly gets sucked into an air conditioning fan. This was a last-minute addition to the script as the original plan - to have her in an elevator shaft - proved too expensive.
Dana Scully says her FBI ID# is 2317-616. 616 is the area code for Grand Rapids, Michigan, where Gillian Anderson went to high school.
This is the second episode to feature Deep Throat.