Treblenk IV
Established in the final draft script of the  first season episode , Treblenk IV was the fourth planet of its star system. As Kirk reported in , the  had just completed a three-month mission involving this planet at the start of the episode.

There is no reference to this planet in the final version of the episode, however, in which Spock merely vaguely states, "After what this ship has been through in the last three months, there is not a crewman aboard who is not in need of rest. Myself excepted, of course."
Unused production material