The 2nd season finale of Star Trek: The Next Generation aired on this day in television history.
That episode was “Shades of Gray,” which aired on July 17th, 1989. It was written by Maurice Hurley, Richard Manning, and Hans Beimler.
In the episode, an alien plant infects Commander Riker during an away mission. The virus could be fatal, if a treatment where he relives his memories of the past doesn’t work.
The episode’s framework was written around a clip show, featuring segments from episodes of the first two seasons. It was the only clip show in the entire Star Trek television series run.
“Shades of Gray” was also the final episode featuring Diana Muldaur as Dr. Katherine Pulaski. Gates McFadden would return as Season 1 character, Dr. Beverly Crusher, for the third season.