In the 23rd century, a mysterious alien probe threatens Earth by evaporating the oceans and destroying the atmosphere, prompting Admiral Kirk and his crew to time travel to 1986 San Francisco, where they encounter a foreign world of punk, pizza, and exact-change buses.

Star Trek IV: The Voyage Home
Captain James T. Kirk and his crew travel back to 1986 San Francisco to rescue the world from an alien threat by finding the only beings able to communicate with the extraterrestrial probe - the distinctive humpback whales.