Elves should have mathematicians, too

I had a dream yesterday morning which involved evacuating the entire continent of North America by walking through a tunnel from California to Chile, and then through another tunnel to London. I don't think the reason for the evacuation was even clear in the dream. But one minute we were standing around talking about job stuff, and then we were heading down into the tunnel.

(Every reason I've come up with for evacuating the continent wouldn't really be solved by doing it through a pedestrian tunnel. Unless it was just a plot to lower population by then collapsing it on everyone.)

astaraelweeper is playing fun games, and I want to play too. Therefore!
- Take five books off your bookshelf.
- Write the first sentence
- Write the last sentence on page fifty
- Write the second sentence on page one hundred
- Write the next to the last sentence on page one hundred fifty
- Write the final sentence of the book
- Let your friends guess what book it is.

( Here are sentences, alphabetical by author. )