10. Assignment Earth - The Continuing Missions Of Gary Seven
The finale of season two of Star Trek saw the USS Enterprise travel back to 1968 on an historical mission. There they encountered the mysterious Gary Seven, a human who was able to transport himself on board the Enterprise and showed no surprise at the appearance of a futuristic star ship orbiting the planet. Gary Seven was a time agent sent back to uncover other missing time agents. When the Enterprise returned to its own time, Gary Seven remained behind to secretly help the planet Earth. The plan was for the story of Gary Seven, played by Robert Lansing, to continue in a spin-off show that would feature the time agent working to assist humanity. Star Trek was already on the verge of cancellation - it wouldn't last beyond season three - but despite the efforts of Roddenberry he couldn't get this show off the ground or save Star Trek. Of course, Star Trek would eventually find itself to the big screen and while Gary Seven was never seen again, some of the ideas behind Assignment Earth found their way into Gene Roddenberry's movie The Questor Tapes.