6 actors appeared in Star Trek. Series Regulars Robert Brown (Jason) played Lazarus in "The Alternative Factor;" David Soul played Makora in "The Apple;" and Mark Lenard played a Romulan Commander and Spock's father, Sarek. The three primary Guest Stars are Lev Mailer, who played Bilar in "Return of the Archons;" Mike Forest, who played Apollo in "Who Mourns for Adonis;" and Kathryn Hays, who played Gem in "The Empath."
With the exception of Joan Blondell, none of the female characters appear in this episode.