/lit/

I'm currently working on a mod for a video game and I'm doing some research into two subjects which I hope you might be able to help me out with.

1) The main character is a prisoner trying to dig is way out from prison. A large portion of this game is spent underground so any books about the claustrophobic atmosphere of mining or prisoner escape would be great.

2) Time traveling and parallel universes that interact with one another is another big theme. I'm looking for material that even if it is fiction, still sounds as if it was based (or actually is based) on real science.

Any suggestions for titles that might help?