There are several TOS episodes where a regular supporting actor or actress is missing without any explanation in the scripts. For example, Uhura is noticeably absent from Turnabout Intruder, Sulu disappears from several S2 episodes, etc. The episodes seem to go on without them, but they are missed.
Could a TOS episode have been successful if Kirk was not in the script at all? For instance, if he was assigned to temorary duty at Starfleet Command, or if he was under medical care for injuries sustained in a Kirk fight, or........
Could a TOS episode have been successful if Kirk was not in the script at all? For instance, if he was assigned to temorary duty at Starfleet Command, or if he was under medical care for injuries sustained in a Kirk fight, or........