Leonard Nimoy returns as director and stars as Mr. Spock. Nimoy allows the actors to take the script and their characters and run amok with them. The story involves time travel which is usually a bad omen.

The film begins with a tender moment. Mr. Spock (Leonard Nimoy), having been regenerated and his kata safely embedded in him, is on Vulcan taking tests in logical thinking, the sciences, and mathematics. The very last question throws Spock into confusion. "How do you feel?" The question was craftily inserted by Spock's mother Amanda (Jane Wyatt reprising her role from the television series). A logical person would answer the question: with my fingers. Spock doesn't understand the question. There is still hope for Spock to embrace his human half.

Meanwhile, an alien probe of unknown origin is on course for planet Earth. The probe's emissions disrupts all power sources rendering space ships and stations devastated in its wake. The probe enters into orbit around Earth and creates a physical connection to the Pacific Ocean. Power is off. The sky is ionized. The planet will be destroyed unless someone can figure out the probe's purpose.

Admiral James T. Kirk (William Shatner) and his skeleton crew decide to return to Starfleet Headquarters to face the criminal charges they face after stealing the starship Enterprise and travel to the forbidden planet Genesis. They arrive in their commandeered Klingon Bird of Prey and begin analyzing the alien signal. To their surprise, the aliens are communicating using the whale song of humpback whales. Unfortunately, humpback whales have gone extinct in the 21st century. The Earth is doomed unless humpback whales can be found somewhere. Humpback whales are indigenous to Earth. The only possible solution is for Kirk to attempt time travel back to 20th century Earth, pick up some humpback whales and return them to the future.

The fun is just getting started once the cloaked Klingon ship lands on Earth. The crew of the Enterprise tries desperately to blend in with the natives. The crew have three missions to accomplish: locate humpback whales, build an aquarium tank inside the Klingon ship, and locate some form of radiation to reenergize the depleted dilithium crystals that power the ship.

First things first, the crew needs money. Kirk decides to pawn the antique reading glasses Dr. McCoy (Deforest Kelley) gave him for his birthday. No worries, Kirk tells Spock, McCoy will buy the glasses for me again.

Kirk and Spock cross a street where they are nearly run down my a motorist. The driver swears at them. Kirk swears back. Kirk explains to Spock that no one pays attention to you unless you swear. Spock incorporates swearing into every sentence the rest of the film.

Chekov (Walter Koenig), accompanied by Uhura (Nichelle Nichols), asks a police officer for directions to the Naval Base at Alameda where they keep the nuclear "wessels". The best source of the radiation they need is the air craft carrier Enterprise.

Kirk and Spock go to the aquarium and meet Gillian (Catherine Hicks), who cares for the whales. While looking through the glass windows of the tank, Spock disappears. Suddenly, Spock is seen performing the Vulcan mind meld on one of the whales. Kirk franticly tries to distract Gillian from looking.

Gillian learns that Kirk and crew are from the future. She asks if Kirk is from outer space. Kirk replies, "I'm from Iowa. I only work there."

McCoy and Scotty (James Doohan) find a manufacturer of Plexiglas in which to build the tank inside the Klingon ship. They have no money so Scotty bribes the manager with the formula for transparent aluminum. Scotty sits at a computer terminal and says, "Computer." Nothing happens. McCoy hands Scotty the mouse. Scotty tries again speaking computer into the mouse. Nothing happens. The manager explains Scotty has to input the data manually. Scotty looks down and says, "A keyboard. How quaint."

Chekov is captured aboard the carrier Enterprise. He escapes only to fall and suffer a brain injury. He is taken to Mercy Hospital. Kirk, McCoy, and Gillian attempt a rescue. To gain access to the hospital, Gillian lays on a gurney and screams in pain. McCoy gives a security guard some medical mumbo jumbo. Later, Kirk asks what McCoy said she has. McCoy replies, "Cramps".

En route to the emergency surgery, McCoy comes across an elderly woman whose kidneys are failing. She is on dialysis. McCoy hands her a pill to take. Later, the same woman is seen telling anyone who will listen that she has been fully cured.

Before Kirk can beam the whales into the Klingon ship, they are released back into the Pacific. A whaling ship is in hot pursuit. When in range, the ship fires a lance only to have it strike metal and fall harmlessly into the ocean. The Klingon Bird of Prey uncloaks above the whaling ship which promptly reverses course.

Just before Kirk and crew are making the sling shot around the sun to return them to the future, Spock confronts Kirk. Spock tells Kirk that since Scotty could not give him precise mathematical data on the water, the tank, and the whales, Spock will have to guess. Kirk looks at Spock with a broad smile on his face. "You Spock? That's extraordinary!" Spock tells McCoy that he doesn't believe Kirk knows the full gravity of their situation. McCoy replies, "Kirk has more confidence in your guesses then most people's facts."

Star Trek IV: The Voyage Home is loaded with one joke coming on the heels of another. Some jokes are visual. Sulu (George George Takei) pilots a stolen Army helicopter to load the glass panels into the cloaked ship. The helicopter is clearly visible. The panels, however, slowly disappear as the enter the ship. The shot is absurd but quite funny. Anyone taking Star Trek IV: The Voyage Home seriously will be seriously disappointed.

When learning Star Trek IV: The Voyage Home involves time travel, most die-hard fans will probably respond with a resounding "Oh No!". Set the absurdities and improbabilities of the story aside and fans will thoroughly enjoy this installment.

In a word, Star Trek IV: The Voyage Home is fun. Enjoy!