If you liked the premise of "Without Warning" you should maybe check out Darwinia (http://www.amazon.com/Darwinia-Novel-Different-Twentieth-Century/dp/0765319055/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1231658035&sr=8-1). Instead of the US, all of Europe disappears over night in the year 1912. The first part of the book is mostly a "Heart of Darkness" story with some info on the political ramification tossed in, the second part is something different I wouldn't want to spoil. A lot of people didn't like the second part, but I loved it all. It's one of my favorite books.