A number of adventure shows that had gone a tad silly recoiled from that after the Batman boom went bust. The Man From U.N.C.L.E. sure did in its final truncated season. Roddenberry sold Trek as an adult sci-fi action adventure. While his memos demonstrate that he liked humor that was appropriate to the story and in character, he was always concerned that the show not get silly or ridiculous.
I think the third season was a bit of an overcorrection, but the show was moved to an adult-time timeslot, and Freiberger was trying everything he could to retain viewers and grab new ones, which included the Melvin Belli stunt casting and the interracial smooch (that he advertised in Variety and The Hollywood Reporter).
I think the third season was a bit of an overcorrection, but the show was moved to an adult-time timeslot, and Freiberger was trying everything he could to retain viewers and grab new ones, which included the Melvin Belli stunt casting and the interracial smooch (that he advertised in Variety and The Hollywood Reporter).