This episode marks the first time Mulder says the famous line: "I want to believe".
The huge portrait of Ruby that Kevin draws was originally done via a computer printout. However, it looked a little too perfect so art department member Vivien Nishi painstakingly wrote out all the 1s and 0s by hand. This took her several days for a shot that lasted a few seconds on screen.
In the file about Samantha that her boss shows Scully, the complete name of Samantha is Samantha T. Mulder, but later in the series it is learned that her second name was Ann.
Joel Palmer, who plays young Kevin, reappears in the series in Season 2 in the possession episode, The Calusari (1995).
This is the first episode in which Mulder fires a gun. He uses it to scare off some wolves.