History Recap / StarTrekS1E19TomorrowIsYesterday

* ChangedMyJumper: Captain Kirk beams down to a 1960s U.S. Air Force base while wearing his Star Fleet uniform. This is probably attributable to [[EarlyInstallmentWeirdness Early Installment Weirdness]], as the producers at the time were likely unaware that the ''Enterprise'' has fabricators which would later produce a 1940s Nazi SS uniform, so a 1960s US Air Force uniform should have been no problem.

* AccidentalTimeTravel: Sling-shotback to the 1960s trying to escape a black star. Interestingly this method proves replicable in later episodes ([[Film/StarTrekIVTheVoyageHome and movies]]).

* AccidentalTimeTravel: Sling-shotted back to the 1960s trying to escape a black star. Interestingly this method proves replicable in later episodes ([[Film/StarTrekIVTheVoyageHome and movies]]).

* AluminiumChristmasTrees: Spock says the fighter approaching them may be armed with nuclear warheads. There was in fact an [[https://en.wikipedia.org/wiki/AIR-2_Genie air-to-air nuclear missile in service at the time.]]

* RecklessGunUsage: Justified; the Air Police who capture Kirk don't know one piece of his gear from another, and a hand phaser looks more like an electric shaver than any 20th-century weapon. Still, they play with it casually and toss it around. If you watch their fingers, they come within a literal hairsbreadth of shooting him or each other more than once. Also justified because they're [[TooDumbToLive military police]].

So, the ''Enterprise'' is trapped 200 years in the past with a "guest" who doesn't want to stay, but they can't let go. The engines are shot. They have no way of contacting Starfleet. There's massive injuries from that star that slapped his ship around like a pinball. [[ArsonMurderAndJaywalking And Kirk's computer is flirting with him.]]

So, Kirk is trapped 200 years in the past with a "guest" who doesn't want to stay, but they can't let go. The engines are shot. They have no way of contacting Starfleet. There's massive injuries from that star that slapped his ship around like a pinball. [[ArsonMurderAndJaywalking And his computer is flirting with him.]]

* FishOutOfTemporalWater: Christopher would be one if the ''Enterprise'' took him back to the future.

* PantyShot: Uhura when Spock helps her up, because for once she's not wearing matching underwear.

* {{Matriarchy}}: The planet Cygnus [=XIV=], where the ''Enterprise'' was put in for maintenance and which gave the crew its flirtatious female personality, is mentioned as being female-dominated.

* StockFootage: Footage of the Earth (going closer and further, inside the atmosphere) on the Enterprise viewscreen is reused from "[[Recap/StarTrekS1E7Miri Miri]]".

* YouWouldntBelieveMeIfIToldYou: Kirk tells his interrogators this when they demand to know how he got in their dark room. Nor would they if he had.

!! Tropes for this episode include:

* TimeyWimeyBall: Here's the solution to their little problem: Mr. Spock says that the best possible course of advantage is to use a slingshot effect like the one they used to arrive in the first place. Theoretically, the whiplash from the sun's gravity would send them into another time warp. At this point, Christopher asks what they will be doing about him and the guard. Spock states that for a moment, they will go into the relative past, and transport both the captain and the guard to points before they were beamed up. The events, though still in their minds, will not have occurred, so there would be nothing for them to report. [[MST3KMantra Don't think about it too much.]]

-->'''Spock:''' Nor have I.

* MoralDissonance: Discussing wiping a man's wife and children from his memory is pretty cold. However, Bones seems to have no objection.

* LittleGreenMen: Christopher states he has never believed in "Little Green Men". "Neither have I," says Spock. When being questioned, Kirk claims to be a little green man from Alpha Centauri.

* DeadpanSnarker: Once more, Bones mentions that Spock admitting to being wrong is a historical moment. Kirk's snarks under interrogation are some of the funniest moments in the show.

* EarlyInstallmentWeirdness: Kirk explains to Christopher that the ''Enterprise'' operates under the auspices of the United Earth Space Probe Agency, rather than Starfleet Command, which wouldn't be introduced until the next episode. The popular [[invoked]] {{Fanon}} explanation is that Kirk was still trying to hide as much about the future as he could...[[VoodooShark which really doesn't explain that much.]] Starfleet Command is instead called "Starfleet Control."