Star Trek” cracks a smile in this fourth cinematic adventure that concludes the three-film story arc that began with “Star Trek II: The Wrath of Khan” and continued with “Star Trek III: The Search For Spock.” Known as much for its humorous tone as for its rather bizarre premise, “Star Trek IV: The Voyage Home” features the former crew of the destroyed Enterprise traveling back home to face trial for their crimes in rescuing the resurrected Spock from the Genesis Planet. They find the Earth being threatened with destruction by an alien probe, which is trying to communicate with the now-extinct race of humpback whales; using their commandeered Klingon Bird-of-Prey, Kirk and his crew slingshot around the sun and travel back in time to 1986, where they hope to snatch a pair of the beasts and bring them back to the future. Many fish-out-of-water jokes ensue as the crew reacts to the various novelties of ’80s San Francisco, with Kirk taking up a romance with a marine biologist (Catherine Hicks) who ends up being the mission’s number-one ally. Nimoy approached “Beverly Hills Cop” screenwriter Daniel Petrie, Jr. to pen the first draft of the screenplay; an earlier version of the film was to feature Eddie Murphy (a self-proclaimed “Star Trek” fan) as a college professor and UFO conspiracy theorist.