Star Trek IV: The Voyage Home - Movie Synopsis & Plot
In the 23rd century, hundreds of starships roam the galaxy, going to places never before explored. They have encountered unimaginable alien races, strange phenomena, and deadly adventures. But now, Earth itself is going to encounter an unstoppable alien force. Just by passing nearby, entire space stations are deprived of energy, ships are left helpless, and the human race is left in jeopardy.
The Enterprise crew, using a Klingon Warbird, are the only ones that can save Earth. Risking their lives, they travel back in time to 1986 where they can retrieve the one species that can save the future: the humpback whale.