Thanks a lot Phaser Two . . . in one fell swoop you exposed two "In Which Two Episodes . . ." games I was saving for my next two turns! "In which two episodes did the Enterprise go to Vulcan" (admittedly a pretty easy one) and "In which two episodes is Scotty mentioned but not shown." The funny thing is, until your game about Scotty, I hadn't realized that they were both from the same two episode! So you can imagine my surprise when I read your post above, especially that it "has always interested me." All I can say is that it has interested me too, but only for the past 24 hours or so. Kudos to you for having noticed it some time ago; some of us are just slower on the uptake than others.
Star Trek is certainly full of these "bizarre coincidences," which also inspired this game. Don't worry, I have many more "in which two episodes" yet to spring on you all . . .
I bet you do! As for noticing it, I'm a Scotty fan - he's my favorite character - so I always found it strange that he wasn't around for two such important adventures. He had a great (and often fun) relationship with Spock and I would have loved to see him interact with Sarek, Amanda or T'Pau.
Sorry for stealing your next two clues.

