Considering all the Star Trek movies and TV shows that have teleported onto screen the past half century — including several hit films featuring the original cast — you might be surprised to learn that the original Star Trek TV series ended in cancellation after just three seasons in 1969.

And Trekkies should thank their lucky stars the original series’ final episode wasn’t the last onscreen voyage of the starship Enterprise. In that episode, Season 3’s “Turnabout Intruder,” airing June 3, 1969, Captain Kirk (William Shatner) and his crew rescue Dr. Janice Lester (guest star Sandra Smith) from a deadly archaeological expedition on the planet Camus II, only for Lester to take over Kirk’s body and try to assert command of the starship.