Comanche moon.

Fourth in publication and second in chronological order, it's a good read that doesn't quite live up to Lonesome Dove. The writing is good, and though it's interesting to find out what happened before the events in Lonesome Dove, I didn't find the story as compelling. There is also a section where a specific torture method described really bothered me and I had to struggle past it in order to finish. Worth the read, but I'm very glad to have started the series with Lonesome Dove.