10 One-Off Star Trek Characters Who Never Left
3. Q
John de Lancie was written into Encounter At Farpoint as a bit of an afterthought. The original story didn't include the Q element at all. Rather, the Enterprise went straight to Farpoint Station, where the adventure unfurled without any courtroom scenes. Roddenberry decided that the episode didn't have quite enough, so Q was added. Although the script clearly called for sequels galore, there initially was no plan for de Lancie to return.
While the Q themselves may have been back, they could easily have been played by different actors, such as they ended up being portrayed on Star Trek: Voyager. But there was something about de Lancie's performance that hooked the producers and the audience. He truly seemed to embody different characters as his Q moved through the different time periods of Earth's history.
Based on his delivery in the pilot, de Lancie was invited back for Hide & Q. Then, his future was more or less solidified, to a point. Maurice Hurley revealed that, had it not been for the Writers' Guild Strike, there was to have been an entire arc for Q in the second season. Unfortunately, this was not to be, and the audience only received a little, insignificant episode named Q, Who...