this is my favorite episode of star trek simply because it a side story with Spock and Scotty on the enterprise and Kirk, McCoy and Sulu. very good chemistry between Spock and Scotty's (specifically the scene in the jeffries tube). i think i have seen this episode over 100 times and it never gets old to me. the last second save of the enterprise was a tension filled scene. ( even though you know it will all work out). and the somewhat corny dialog such as "i am for you Sulu" when the program comes to take her next victim. even though it is somewhat cheesy its not cheesy enough to bring down the episode. over all it is a must see for any star trek fan and if you haven't seen or heard of star trek check your pulse because you have been dead for 40 years.