The most famous episode in franchise history, "The Trouble with Tribbles," is one of the highlights of the second season of Star Trek: The Original Series. A deserved classic, the humorous story centers on an ever-expanding mass of furry creatures that memorably rain themselves down on top of Captain Kirk (William Shatner) and into the middle of a Federation-Klingon showdown. It inspired one of the most memorable episodes in the spin-off series Deep Space Nine, "Trial and Tribble-ations." Also in the second season, the Vulcan culture of Mr. Spock (Leonard Nimoy) is fleshed out in "Amok Time" (in which Spock is faced with the possibility of killing his captain and friend) and "Journey to Babel" (introducing Spock's father, played by Mark Sarek, in what would turn out to be a long-recurring role). A new character, navigator Pavel Chekov (Walter Koenig), was introduced; his Monkees haircut was intended to appeal to the younger audience, but he was also a Russian, which at the height of the cold war reflected Gene Roddenberry's optimistic vision of a more enlightened future. Other social-commentary opportunities presented themselves in "The Omega Glory," "The Doomsday Machine," and "Assignment: Earth," the last also one of those periodic opportunities to scrimp on the budget by time-traveling to an earlier version of Earth. Another example was "A Piece of the Action," a comic episode set in the Roaring Twenties and memorable for, among other things, Kirk's teaching a made-up card game called Fizzbin. In other significant episodes, "I, Mudd" saw the return of the bounder from season 1, "The Changeling" was the original inspiration for the first Trek feature film a decade later, "Wolf in the Fold" (penned by the author of Psycho) provides an example of the series' great writing, and "Mirror, Mirror" introduced the concept of the parallel universe inhabited by vicious, amoral counterparts of the regular crew, another theme later borrowed (more than once, and to good emotional effect) by DS9.

the writing started to slip some,but on the whole the second is just fine

as the second season got started it looked like it was going to be another great season,but as time went on the stories began to slip into the realm of lost in space,but don't get me wrong this season was still a very good one and as i love trek i love this season but you could see the quality begen to slip some as the season went on. not as many extras as the first season but still a great set.

Classic Sci-Fi

Star-Trek fans will definitely enjoy this collection of the best science-fiction show ever produced. This album includes every episode of the second season (out of three) originally aired on TV in the late 1960's. But: without commercials, and with excellent picture quality! Truly a collector's item. And it comes with a photo booklet and unique hard-plastic case.

The best season

The second season of the original Star Trek is the best. My favorite from this season is "mirror,mirror" There are a few that aren't very good, however, like "assignment:earth" which was intended as a pilot for a series that didn't get produced. However, there are more great episodes than bad in this season.