How did they get back in “City on the Edge of Forever”?

I’ve never understood how Kirk, Spock, and Bones got back to the present at the end of “City on the Edge of Forever”. Going back to 1930 is simple enough, they stepped through the portal at the right moment, but there was no portal on their end! How did they get back?

Finding an answer is proving to be difficult because even after trying numerous search-term permutations, I only managed to find a single mention of the discrepancy.

I can understand if maybe they wanted to focus on the emotion and stuff of the episode, but it’s a science-fiction show, and this was one of the first incidents of time-travel in the whole franchise, so getting back is a fairly big issue that can’t just be glossed over.

Best Answer

There is a part in the episode at approx 12:30 where Kirk asks the Guardian if they are successful what will happen. The Guardian tells them all will be set back to normal and they will be returned as though nothing happened. The Guardian sends them back. Also notice they come back with uniforms back on, where at the point in the episode, Kirk and Spock do not have theirs on.

Edit addition:

To clarify something to bring this all together for you. How did Kirk, Spock, and McCoy go through the portal in the first place? They jumped. They jumped in, McCoy first, followed by Kirk and Spock. They came back in the same manner, only Spock and Kirk come back first because they entered the timeline first. The jumping motion was one contiguous motion as seen from the crew left on the planet. Scotty also says to them, "You just left." The Guardian puts them back just as he found them, jumping through the portal.