The scene where O'Brien buts heads with his counterpart Cardassian and sings the song with his former Commander was suggested by Michael Piller to help diffuse the very tense situations that would develop in this episode..
	Sharing his credit with Mark Lenard (Sarek), Marc Alaimo has had the honor of playing three different aliens - an Antican in "Lonely Among Us", a Romulan in "The Neutral Zone" and a Cardassian here. He would later go on to get the famous recurring role of Dukat in spinoff DS9.
	The facial hair on the Cardassians will never be seen again in Trek.
	John Hancock (Adm Haden) starred in "Foul Play" and "L.A. Law" and later died of a heart attack in 1992.
	Michael Westmore and Bob Black tried to give the Cardassians a "snakelike" look, although the makeup took two and a half hours to apply. The helmets seen were not used again.
	Greg Jein transformed the original Nebula class design seen in "Future Imperfect" into the U.S.S. Phoenix here, while Rick Sternbach created the Cardassian Galor-Class cruiser basing it on a scorpion like design with an Egyptian look.

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