The Enterprise collides with a black hole and is thrown back to Earth in the 20th century, where they must find a way back and erase any trace of their presence. Matters become complicated when they rescue an Air Force pilot and cannot return him without changing history...but if he disappears that will change history as well.
Elenco: William Shatner , Leonard Nimoy , DeForest Kelley , Majel Barrett , Walter Koenig , George Takei , Nichelle Nichols , James Doohan , Majel Barrett , Bill Blackburn , Frank da Vinci .