Tomorrow is Yesterday
The Enterprise is accidentally sent back in time to the 1960s, and beams aboard an air force pilot. The future hangs on his safe return to Earth.
The gang finally takes the time warp promised in The Naked Time, using the infamous slingshot method. The time paradoxes provide some substance, but this is also the show's first great comedy. Such moments as the interactions with the "female" computers, Christopher's first glimpse of Spock after dismissing "little green men," and the sergeant's bowl of soup are hilarious and unforgettable. Captain Christopher is a likeable "average Joe" character, with the right mix of wide-eyed curiosity and Cold War-fueled suspicion. More excitement happens at the air force base, though one wonders why they need to collect evidence that won't have been recorded anyway . . . Still, the mind-boggling details of time travel are smoothed over with spirited humour and fast-paced hijinxs, foreshadowing the masterful The Voyage Home.
Spock Saves the Day: Spock warns the tractor beam will crush the plane, discovers Christopher's importance in history, rescues Kirk from interrogation, and halts Christopher's escape.
Oops: Spock realizes his own error in not checking for contributions by the captain's descendants, and corrects it.
Developments: Spock's shipmates often grapple with his "alien" behavior, but this is the first time his mere appearance has a literal jaw-dropping effect on humans. The two men of the 20th century, having never encountered a Vulcan, are understandably awed. Again, a simple head band helps Spock to avoid similar problems in The Voyage Home.