- Agent Arthur Dales: Do you know what an X-File is?
- Fox Mulder: It's uh... Yeah, it's an unsolved case.
- Agent Arthur Dales: No.
- [He says, like a teacher correcting a student]
- Agent Arthur Dales: It's a case that has been Designated unsolved.
- Young Arthur Dales: An X-File?
- Dorothy Bahnsen: Yes, unsolved cases. I file them under X.
- Young Arthur Dales: Why don't you file them under U, for unsolved?
- Dorothy Bahnsen: That's what I did, until I ran out of room. Plenty of room in the Xs.