After an accidental overdose of the stimulant cordrazine, Dr. McCoy jumps through a time portal on a deserted planet and ends up on Earth in the 1930's.
Air Date: 04/06/67
Director: Joseph Pevney
Here we are, perhaps the finest science fiction television episode ever. Time travel in its finest as penned by the immortal and enigmatic Harlan Ellison....Perfect acting by Deforest Kelley, Leonard Nimoy, William Shatner, and Joan Collins really makes this episode sparkle. What makes this episode so great? It's the message of friendship, risking everything, and doing what must be done against all odds. You can't help but be touched by the look on Kirk's face during the climax. The fact that this episode concludes with the only swear word in all three seasons is rather fitting based on what the crew had gone through.