StarTrek.nl - Planet

The City on the Edge of Forever

McCoy accidentally receives an overdose of cordrazine as the Enterprise encounters turbulence. He beams down to an unexplored world where he enters a time-travel device known as the Guardian of Forever and changes history in the 1930s. Kirk and Spock also return to the 30s, where Kirk falls in love with peace activist Edith Keeler. When McCoy is finally located, Kirk must allow history to run its course, resulting in Edith's death, or he will leave history altered irrevocably, with no chance of returning to the future or the Enterprise.

The Original Series, seizoen 1