In this book, as in so many other works of science fiction, Earth is beset by a Malthusian trap. Luckily, humans have discovered how to teleport themselves to other locations in the universe. This ability allows humans to colonize other planets.
Since the cost of teleportation is high, colonists must be able to survive in unknown and hostile territories. Some students are trained to lead new colonization efforts and the last part of their training requires them to survive for several days on an unknown planet.
The book follows a group of students on this final part of their training. Due to certain circumstances, the students are not rescued after several days and they begin setting up their own colony.
Our hero unites the students and begins the process of establishing a civilization. Almost immediately after the basic needs are being consistently met, someone else stands up, gives a pretty speech and is elected "mayor." (I found this a bit far-fetched, despite the low opinion I have of democracy, but it allowed the story to move along).
Of course, the democratically elected leader turns out to be an idiot (though he is a good politician) and the colony is soon over-run by animals because they followed their leader and failed to listen to our hero. The colony survives and elects our hero mayor and they all live happily until they’re rescued.
The book was sort of like a Lord of the Flies set in space. As far as re-civilizing stories go, Earth Abides is much better, but Tunnel was entertaining. The changes in the government were the interesting bits, but they seemed a bit hurried and consequently unbelievable. The other interesting bits revolve around the way people act outside of civilization, which I always find interesting.