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 who appeared on "The Original Series" later made guest appearances as different characters in later series, most notably Majel Barrett, who not only provided the voice for most Starfleet computers in episodes of every spin-off series (including a single appearance on "", where the computers normally did not speak at all), but also had the recurring role of Lwaxana Troi in "The Next Generation" and "Deep Space Nine". Diana Muldaur, a guest star in the episodes "Return to Tomorrow" and "Is There in Truth No Beauty?" of the original "Star Trek" series, played series regular Dr. Katherine Pulaski in the