On this day in the Star Trek universe (1968):

Star Trek
Season 3. Episode 1.

Episode entitled: Spock’s Brain.

Released September 20, 1968.

Directed by Marc Daniels.

Written by Gene L. Coon / Lee Cronin, Arthur H. Singer.

Created by Gene Roddenberry.

Music by Alexander Courage.
 
Cast: 

William Shatner, Leonard Nimoy, Nichelle Nichols, DeForest Kelley, James Doohan, George Takei, Majel Barrett, Walter Koenig, Marj Dusay, James Daris, Sheila Leighton, Bill Blackburn, Frank da Vinci, Roger Holloway, Pete Kellett, Jeannie Malone, Eddie Paskey, Frieda Rentie.