I got a chance to see Star Trek 4: The Voyage Home. I would have seen it earlier, but it was always checked out at my local library, whenever I visited. I guess that's a testament to its enduring popularity.
The premise of the movie is that an alien spaceship is attacking Earth, sending out weird messages that pretty much destroy all technology. This is happening at the same time our heroes are returning to Earth. So they're the only Earth spaceship which still works, meaning they're the only ones that can save the planet.
It turns out that the aliens are whales. Space whales. I thought that was a joke, but it's 100% serious. About every million years or so, the alien space whales stop by Earth, chat with a few humpback whales, then go back to their own planet. But humpback whales are extinct at this point in history, so our heroes go back in time to 1986 to find some whales.
I'm not a big fan of introducing time travel into the movie series at this point. That just begs the question of "why didn't they use time travel to avoid any of the problems in the previous movies"? But to be fair, the original Star Trek TV series featured a lot of "we're time travelling back to the same year this series was made", probably because it's cheaper to film live in San Francisco than it is to build a future San Francisco set and film there.
So our heroes crash land in 1980's San Francisco, and just enough of their computer equipment has failed, in order to give everyone a job to do. Kirk and Spock are the main characters, so they have to find the whales. McCoy and Scotty have to find some kind of whale cage, while Sulu finds a way to transport it. Uhura and Chekov have to find a nuclear power source to run their ship.
The movie is pretty funny, with a lot of "our heroes are super confused" jokes, and thankfully, there was only one joke that fell flat, because it relied on a 1980's pop culture reference that I've never heard of before, ever. It was cute to see Spock start swearing in order to fit in, just because that's so out of character for him. It was funny to see Scotty try and fail to control a computer by talking to Siri, because he ended up looking like an idiot who talks to machines. It was neat to see McCoy argue medicine with a real doctor, and it was at least kind of funny that nobody understood Chekov's accent. Kind of.
I can totally see why non Star Trek fans enjoy this movie. It's not high philosophy and technobabble! It's a "fish out of water" humor script, with occasional action sequences (they get the nuclear power source by robbing a military base). There's a minor romance element to it, which was better than I expect, compared to the original series, where the "romance" was mostly an excuse for hot girls to wear revealing outfits.
I'd say the only think I didn't really like were the parts where the movie got put on hold for a few minutes, so they could deliver a "save the whales" speech. That was just as heavy-handed as the "buy organic food!" lectures in Nancy Drew Diaries 9, whose name I don't remember, because I just remember it as the organic farming book.
Also, if I'm being picky, I didn't like how our heroes focused on saving one specific pair of whales, when they easily could have taken any pair of whales from the ocean, no problem. Nope, our heroes have to focus on the only pair of whales in the world that are in captivity and have media attention on them. Guys, you're only making your job harder on yourself!
Overall, a great film, space whales and all. It was fun, funny, and well-balanced. I'd say it's my favorite of the movie series so far! I can see why people enjoy the (loose) trilogy made up of Movies 2-4. I hope movie #5 is just as good, but I know that it won't be, because it's the movie everyone hates. Sad.