Don't be misled by my title, this was a great film. One of the best of the original Star Trek series. Directed by Leonard Nimoy (Spock for those of you who aren't familiar with such things) this film is about the crew of the U.S.S. Enterprise, James T Kirk et. al. who need to save earth from a destructive probe from far away in space. The probe is accidentally destructive, it's sending a communication to earth and when there is no reply it ups the power. Because the signal is sent at the earth's oceans the water starts to boil, there are incredible storms and cloud coverage of the earth increases very rapidly. It turns out that it is necessary for the crew to travel back in time to 1980's earth, San Fransisco to be precise where they try to blend in.
Due to events in previous Trek films they are on board a Klingon bird of prey which is on it's last legs and they get trapped on earth (and in the 20'th century) so the film is about doing the job they needed to to save the world in the 23rd century and managing to repair the ship to get them home.
There is a lot of humour in this film, the crews attempts to get the materials they need and to 'blend in' to a totally alien culture, which we know well, is done very well. Occasionally things are a little OTT but thats not surprising and forgivable because this is a trek film.
The best scene is probably when Chekov the russian is beamed aboard an AMerican Nuclear submarine in order to collect high energy photons (or some such) from teh reactor. So there's this little friendly russian with some weird equipment on an american nuclear sub in the midst of the cold war.
There area a lot of nice touches in this film and although I think The Undiscovered Country is probably better this is a film more likely to be enjoyed by none Trekkers (NOT 'trekkies', sorry) and a very good stand alone story.