It starts with cadets at an academy preparing for life on an uninhabited planet. They pass through the tunnel and start putting their training to practice. They've been warned about the one animal that is the dominant predator. They are to identify it and plan accordingly. The only problem is that they can't find this dominant or apex predator. All the animals are docile. Just when they think all is going smoothly one of the smaller docile animals that some have turned into pets suddenly metamorphosize into an aggressive killing machine. After surviving its onslaught the animal transforms back into the cuddly pet until the next time.
Done with college and seminary, I started reading for pleasure for the first time. This is when I started picking an author and devouring as many of his or her books as possible. One of the first was Heinlein. I skipped his juvenile books, Tunnel was number nine in this series. Ray took the phrase "Holy cows make the best hamburger" to a vengeance. I discovered Stranger in a Strange Land. The holy cow here was religion. He takes the supposition that when people die they go to whatever afterlife they believe in. Vikings go to Valhalla, Muslims to paradise, Christians to heaven so and so forth. He created a word: Grok. It took a while for me to grok what he was thinking about. The ending is a little cheesy, but coming out of a Southern Baptist Seminary and learning how to dream a new dream after years of believing I would one day pastor a church, this book broke some of the chains fundamentalism had fastened around me.
The Moon is a Harsh Mistress. It's a fascinating concept of what it would take to colonize the moon. It was only natural to assume that those who moved there would be treated the same as all colonies. The mother country or this case mother Earth would treat them like children while draining them of natural resources giving little to nothing in trade. Eventually those on the moon revolt and have one huge weapon: gravity. They can launch boulders at earth and they land with a force of nuclear bombs.
I Will Fear no Evil is about a wealthy man whose body is deteriorating and he uses his money to create a new body for his mind, and this time he wants to be a woman. This was light years ahead of the transgender, sex change revolution we're witnessing today.
Heinlein took the idea of large objects being used to bombard earth to another level with Starship Troopers. One of the biggest criticisms of this book and the movie is that it glorifies a militaristic society. What those critics miss is the punchline. Yes it's a society that works, but only if you're killing bugs.
Lastly this one soured me on RH. Time Enough for Love. He took the idea of sacred cows a little too far for me.
It's a long complicated story. It involves the ability to regenerate your body and become twenty again as many times as you want, or if you're tired of living hit the suicide button.
There is one man who has hit the suicide button, but doesn't die. He recounts to others all his memories. Then he decides to travel back in time to meet his parents and not saying specifically but Oedipus rears his ugly head.