23 Years Ago: Leonard Nimoy Guest Starred on "Unification I"

It was 23 years ago today -- November 4, 1991 -- that the landmark Star Trek: The Next Generationepisode "Unification I" debuted. The seventh episode of season five, it centered on Ambassador Spock's surprise visit to Romulus, with Picard sent by the Federation to investigate the circumstances surrounding the esteemed Vulcan's apparent disappearance.

Among other key elements/tidbits:

-- Much of "Unification I" was filmed after "Unification II."

-- A placard reads, "Gene Roddenberry: 1921-1991." Roddenberry had died on October 24, 1991

-- Dennis McCarthy's score for this episode received an Emmy Award nomination.

-- Malachi Throne, who played Pardek, had turned down the role of Dr. McCoy on The Original Series, but did appear in several TOS episodes. Throne passed away in 2013.

-- Stephen Root, who played Captain K'Vada in both parts of "Unification," is a veteran character actor best known for his role as Milton Waddams in the cult favorite movie Office Space. More recently, he's recurred on Justified and Fargo, and in September he guest starred on an episode of The Big Bang Theory.

-- Nimoy's appearance on TNG helped set the stage for the imminent release of Star Trek: The Undiscovered Country.

What's YOUR favorite memory of "Unification 1"?