The Original Series was a work in progress with two fundamental concepts introduced as retcons late in season 1.

We may receive a commission on purchases made from links. It's important to note that "essential" episodes of "Star Trek" are not necessarily the best ones. To this author, "essential" denotes ...

A cinematic obsessive with the filmic palate of a starving raccoon, Rob London will watch pretty much anything once. With a mind like a steel trap, he's an endless fount of movie and TV trivia, borne ...