Roddenberry’s response to the scheduling decision has been characterized in various ways. His own account was that scheduling the show in a death slot was equivalent to canceling it in advance — that it was NBC’s way of technically renewing while practically ensuring the show would fail — and that given this reality, he chose not to invest the same energy in a production that the network had already decided to let die.
Freiberger came to the third season with significant television producing experience but without Roddenberry’s specific creative vision for what *Star Trek* was. The episodes produced under Freiberger’s supervision were often criticized by fans and critics as lacking the thematic ambition that had characterized the first two seasons. Some of the season’s episodes are considered among the worst the original series produced.
The third season also had a reduced budget. NBC’s scheduling decision was accompanied by financial decisions that reduced the per-episode investment. The science fiction production design — the sets, the effects, the visual ambition — that had been a defining characteristic of the show became more constrained as the budget tightened.
There were exceptions. “All Our Yesterdays” is frequently cited as a third-season episode that maintained the show’s quality. “Day of the Dove” and “Spectre of the Gun” have defenders. Even within the diminished third season, the production team was occasionally capable of the work that had characterized the earlier seasons.
The final episode, “Turnabout Intruder,” aired on June 3, 1969. It was not, by most accounts, a dignified ending. The network that had commissioned the show, funded the second pilot, and carried it for three seasons let it conclude without ceremony.