Garak's first name is revealed here: Elim.
This episode first introduces the Obsidian Order, the ruthless Cardassian intelligence agency for which Garak used to work.
In this episode, we learn that Dr. Bashir's middle name is Subatoi.
Bashir: (after Garak tells the third version of his downfall) Why are you telling me this, Garak?
Garak: So that you can forgive me, why else? I need to know that someone forgives me.
Quark: (as Garak starts his third bottle of kanar) Come on, Garak, don't you think you've had enough?!
Garak: On the contrary, anyone who talks about the numbing effects of your liquor is severely overstating the case!
Enabran Tain: I want him to live a long, miserable life. I want him to grow old surrounded by people who hate him, knowing that he'll never come home again.
Bashir: What a lovely sentiment.
Enabran Tain: And it's from the heart, doctor.
Bashir: And so they exiled you.
Garak: That's right! And left me to live out my days with nothing to look forward to but having lunch with you.
Bashir: I'm sorry you feel that way. I thought you enjoyed my company.
Garak: Oh, I did! And that's the worst part. I can't believe that I actually enjoyed eating mediocre food and staring into your smug sanctimonious face.
Bashir: Of all the stories you told me, which ones were true and which ones weren't?
Garak: My dear Doctor, they're all true...
Bashir: Even the lies?
Garak: Especially the lies.
Garak: Did anyone ever tell you that you are an infuriating pest?
Bashir: Chief O'Brien, all the time, and I don't pay any attention to him either.
Bashir: I'm a doctor, not a botanist.
(about the Obsisian Order)
Odo: They're the ever-watchful eyes and ears of the Cardassian government. It is said that no citizen can sit down to a meal without each course being carefully documented.
This episode marks the first appearance of Enabran Tain. It was intended to be Tain's only appearance, but as with Garak, the character proved popular with fans and the producers were impressed with Paul Dooley's performance that the character would make several more appareances and his relationship with Garak will continue to evolve. He would next appear in the season three episode "Improbable Cause".
Julian and Jadzia look at a display labeled "File 839472-58" while trying to find out what's wrong with Jadzia's plant. Writer Joe Menosky began including references to the number 47 in almost every episode of Star Trek since season four of The Next Generation. It is an in-joke, referring to The 47 Society at Pomona College in California, a college which Menosky attended.
Cirroc Lofton (Jake Sisko) does not appear in this episode.
The Obsidian Order was originally supposed to be called the Grey Order. The name was changed once members of the crew realized that Babylon 5 (which was also airing first-run episodes at the time) already had an alien group called the Grey Council.
Not surprisingly, Andrew Robinson counts this as his favorite episode.
In an interesting bit of foreshadowing, Garak hands Bashir a data rod with a story set in a futuristic war between the Cardassians and Klingons. The fourth season of Deep Space Nine would begin with a war between the Klingons and Cardassians with results the author of Garak's tale more than likely didn't expect.
Garak reveals several elements from his past in this episode. However it's unclear which ones he was lying about. The only things revealed about Garak in this episode that are more or less confirmed by later episodes are his first name (Elim) and his service with the Obsidian Order.
Bashir says "I'm a doctor, not a botanist." This is a nod to Star Trek: TOS and specifically Dr. McCoy who would often say "I'm a doctor, not a (insert numerous other professions.)"
Death By Ecstasy
The plot of this episode is nearly identical to the short story Death By Ecstasy by Larry Niven, in which a man is murdered by a device like the one implanted in Garak. It was first published in 1969, and done as a graphic novel in 1991.