Your reading this for one of possibly two reasons:
A) You want to know how others feel about this final episode that you've also seen or,..
B) You have no idea about Star Trek
Given the popularity of this series, I'll assume "A" is your reason. However, if your the rare "B" person, then I recommend avoiding this episode until you've watched at least a few episodes of The Next Generation.
This wonderful 2-hour finale utilizes the history of these characters and plots beautifully and with reverence.
The lead character of the series, Jean Luc Picard, finds that he is inexplicably shifting between 3 time periods within his own liftime (past, present and future). Once he finds the reason for this, things become more complex and intriguing. His eyes are opened to an even greater threat than what he had perceived to be his own. As wonderful a premise that is, the subplots greatly enhance the characters and draw you into the story.
For example, Tasha Yar, a well regarded character in the series was killed early in the shows run. In his shift into the past, Picard once again sees her alive, accompanying him to the Enterprise for the first time (again, ironically). Once he returns to the present, he laments over having seen her again. A beautifully played little scene.
The main story combined with these subplots makes for one of the best written series endings ever in TV history.
Let's hope that future TV series (not necessarily Trek, of course) have the opportunity to do the same.
