Stardate 3134.0: 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.
written by Harlan Ellison
directed by Joseph Pevney
music by Alexander Courage
Guest Cast: DeForest Kelley (Dr. Leonard McCoy), James Doohan (Mr. Scott), George Takei (Lt. Sulu), Nichelle Nichols (Lt. Uhura), Joan Collins (Sister Edith Keeler), John Harmon (Rodent), Hal Baylor (Policeman), David L. Ross (Galloway), John Winston (Transporter Chief Kyle), Bartell La Rue (Guardian voice)
LogBook entry by Earl Green