editor, John D. F. Black, was also looking to leave, so Roddenberry gave Fontana the task of rewriting the episode "This Side of Paradise". Both Roddenberry and the network were satisfied with Fontana's work, and she became the new story editor instead of Roddenberry's secretary in September 1966. Fontana subsequently came up with the ideas for the episodes "Journey to Babel" and "Friday's Child". There were other works that she was formally credited with based on the Writers Guild arbitration that were only re-writes of episodes. She later recalled completely re-writing "The Ultimate Computer", as the original writer was unwilling to make the recommended changes. She said that this was a common issue; "You either had to do a light polish, sometimes just on dialogue and then you took no credit for that of course, because it would not be fair, but when you really do a total script overhaul, then it has to automatically go into the Writers Guild for arbitration." She was one of four writers to re-write Harlan Ellison's "The City on the Edge of Forever", alongside Roddenberry, Gene Coon and Carabatsos who had all made changes at different times to Ellison's displeasure. Fontana's draft, submitted on January 23, 1967, was superseded by three further versions by Roddenberry. Fontana left the team prior to the third season, but continued to write scripts on a freelance basis. These included "The Enterprise Incident", "That Which Survives", and "The Way to Eden"; the last two were credited under the pseudonym Michael Richards. She disliked some of the changes made in "The Enterprise Incident", such as the size of the cloaking device, and found working with her replacement difficult, as the new story editor did not understand the basics of the series, such as what the transporter did and how old Leonard McCoy was meant to be. Leonard Nimoy credited her for expanding Vulcan culture within Star Trek. He was unsure when "This Side of Paradise" was proposed, as Fontana had changed the romantic lead from Hikaru Sulu to Spock but he enjoyed being able to act out emotions with the character, and also praised her work on "Journey to Babel" and "The Enterprise Incident". Nimoy also felt that unusually among Star Trek writers, Fontana was able to write believable female characters who were fully developed in the screenplay. Fontana's freelance status meant that she could write for several series, including