Star Trek: The Animated Series were added to the cast—claiming that Sulu and Uhura were of importance as they were proof of the ethnic diversity of the 23rd century and should not be recast. Nimoy also took this stand as a matter of principle, as he knew of the financial troubles many of his "Star Trek" co-stars were facing after cancellation of the series. Koenig was not forgotten, and later wrote an episode for the series, becoming the first "Star Trek" actor to write a "Star Trek" story. Koenig wrote "The Infinite Vulcan", which had plot elements from the original "Star Trek" episode "Space Seed"
Star Trek: The Original Series that have adopted period Earth cultures (Prohibition-era Chicago, Nazi Germany and ancient Greece, respectively). Two episodes depicting time travel ("Tomorrow Is Yesterday" and "") conveniently place "Enterprise" in orbit above 1960s Earth; a third ("The City on the Edge of Forever") places members of the crew on 1930s Earth. Several publications have ranked the ten best episodes of "Star Trek": In 1983, Leonard Nimoy hosted a one-hour special as a promotional tie-in with the film "", in which he recounted his memories of working on the original series and explained the origins of things such as the Vulcan nerve pinch