7. Dagger Of The Mind (Episode 11)
The Plot: The Enterprise finds that the head doctor on the Tantalus Penal Colony is conducting cruel and unusual experiments on his prisoners.
The Screw Up: This is the first episode to feature the now famous Vulcan Mind Meld. Spock refers to is as a hidden, personal thing to the Vulcan people, part of our private lives. Well, guess what? It's not. Spock apparently has a flair for melodrama and was just trying to pretend that this was some super double secret Vulcan thing that he did that his human bros wouldn't understand, because he ends up employing it a s**t-ton more times in the television series and movies, and several other Vulcans do it in every single other Star Trek series there is.
Cool Trivia: This episode was parodied in the
South Park episode Roger Ebert Should Lay Off the Fatty Foods.