Star Trek IV: The Voyage Home (1986)
I didn’t expect much given the ludicrous premise, but… I loved it. William Shatner got his acting chops back, and each member of the Enterprise got something to do. I did wonder though, with all the times they show off their futuristic tech, why didn’t it result in another alternate timeline? But that’s a minor quibble. The movie was charming and irreverent.
8/10
You can tweak the past, but as long as you don’t kill anybody, the future is probably safe. I’m sure the investigation into the mysterious Russian captured on board the aircraft carrier Enterprise was closed pretty quickly, and the file buried just as fast. People just don’t vanish from an elevator.
And as long as the kidney lady doesn’t go on to win the lottery, and give all her money to some fellow named Khan Noonien Singh who’s she’s been pen pals with, there’s nothing to worry about. 😉