This is a new book by TP co-creator Mark Frost that provides the "back story" for Twin Peaks starting with the Lewis & Clark expedition. The supernatural aspects of the town are delved into in some detail – clearly as a setup for the forthcoming TV miniseries, as well back stories on the various characters – some of which we knew from the original series, and some of which we didn't. (A significant glitch here where Norma Jennings' mother is said to be deceased when she was on the series, and the story of how Big Ed and Nadine got together doesn't quite fit with the story he told on the show. But I'll forgive it).
Very interesting book. I really liked the back story and think it fits with the show – even though it has the weird coming from a little different place from where I thought it did. But if you like Twin Peaks, you'll love it.