The original Star Trek and the original Mission: Impossible were both filmed at Desilu studios. As a result, many character actors were seen on both shows in memorable ways. There is an interesting continuation of this in the second MI series and in Star Trek: The Next Generation. John de Lancie plays the unpredictable main antagonist in both pilot episodes.
Voice on Disc: [Line repeated near the beginning of each episode in the series as Jim Phelps listens to the tape/disc containing his instructions and setting up the episode storyline]
Your mission, Jim, should you decide to accept it...