While there were some changes made for Season 2 of the second Star Trek series created by Gene Roddenberry himself, the most notable was the introduction of this season's exclusive medical officer Dr. Pulaski, played by Diana Muldaur who previously played two different guest roles in the Original Series. In contrast to Dr. Crusher's (Gates McFadden) cool, antiseptic character so far, Pulaski evoked more of TOS's Bones (with her sometimes-abrasive attitude and an impish sense of humour) which wasn't a bad thing. Discs 1 through 5 contain all 20 season 2 episodes. Disc 6 contains about 80-minutes worth of extras.