Tomorrow is Yesterday

TOS Season 1 Episode 19
Air Date: January 26th, 1967

This episode is the accidental version of Star Trek IV: The Voyage Home. The Enterprise is discovered over the skied of the United States in the mid 1960s. They accidentally went back in time when avoiding a black hole. There isn't much to the episode. A US fighter jet goes to investage, the Enterprise accidentally cause the fighter to break up so they transport the pilot aboard. Then they have to figure out a way to get rid of any film of the Enterprise that the fighter recorded in it's black box.

Once they get it back (though not on the first try) they figure out they can do a time warp around the sun and transport the pilot back at the exact time he left, with no memory of what happened while they fly past earth going through time.

The science is silly in this one though it does pave the way for my second favorite Star Trek movie.