"The Infinite Vulcan" is the seventh episode of the first season of the American animated science fiction television series Star Trek: The Animated Series. It first aired on NBC on October 20, 1973, and was written by Original Series cast member Walter Koenig. It was the actor's only involvement in the series, as he had not been hired to voice Pavel Chekov in the animated version due to budgetary limitations. With "The Infinite Vulcan", Koenig became the first member of the Star Trek cast to write an episode for the franchise. As with the rest of the first season, the episode was directed by Hal Sutherland. Set in the 23rd century, the series follows the adventures of Captain James T. Kirk (voiced by William Shatner) and the crew of the Starfleet starship Enterprise. In this episode, the crew visit a planet inhabited by plant-based lifeforms and must save the life of Science Officer Spock (voiced by Leonard Nimoy) after he is abducted by a giant clone of Dr. Stavos Keniclius (voiced by James Doohan). Koenig was hired to write the script after some of his work was passed from Susan Sackett to series creator Gene Roddenberry. Koenig found the writing process for the episode unenjoyable, due to the number of re-writes required. Further additions were made by Roddenberry, including talking vegetables as characters. When the producers offered him a second episode, Koenig turned it down. "The Infinite Vulcan" received a mixed reception from critics, who suggested that the writing could have been better, but others included it in lists of the best episodes of The Animated Series. Plot While exploring the newly discovered planet Phylos for possible Federation colonization, Lt. Sulu picks up a walking plant, called a Retlaw, and is poisoned by a stinger. The plantlike alien beings who inhabit the planet approach the Enterprise landing party and their leader, Agmar, saves Sulu's life. The Phylosians say they were nearly wiped out by a mild terrestrial disease that was brought to the planet by Dr. Stavos Keniclius, a Terran scientist who survived Earth's Eugenics Wars. A giant clone of Keniclius, named Keniclius Five, kidnaps First Officer Spock. Keniclius has survived through the centuries by periodically transferring his consciousness into a new, more advanced clone body. He believes the galaxy is as war-ravaged as Earth was when he left it. He plans to enforce peace on the galaxy with the