Star Trek IV: The Voyage Home is a 1986 American science fiction film, the fourth installment in the Star Trek film franchise based on the television series Star Trek. The second film directed by Leonard Nimoy, it completes the story arc begun in Star Trek II: The Wrath of Khan (1982), and continued in Star Trek III: The Search for Spock (1984). Intent on returning home to Earth to face consequences for their actions in the previous film, the crew of the USS Enterprise finds the planet in grave danger from an alien probe attempting to contact now-extinct humpback whales. The crew travel to Earth's past to find whales who can answer the probe's call.