It's one of the most bizarre episodes of the original Star Trek, filmed in a way that you could cut out all the Star Trek scenes and be left with a short pilot episode of this "Gary Seven" spinoff. Did it belong in the Star Trek universe? Would it have even worked?
When I watched it again recently, it almost felt like a Doctor Who rip-off (with the time-traveling genius, sonic screwdriver, and young female sidekick), but after looking into it some, apparently there isn't any evidence that it was influenced by Doctor Who (which wasn't all that big at the time, and was only shown in the UK).
All that aside, it's a fun episode, and I think Gary Seven made for an interesting character to watch. I can't help but wonder if we missed out on another classic series.
I was thinking exactly that earlier, but I didn't feel like editing my post.