DP loves Terry Pratchett books so thought I'd him get one for christmas but I'm a bit bemused by just how many books he's written! DP seems to have about ten books (all part of something called Discworld?). I've like to get him a book that isn't part of a series so he can read it on its own - does anyone have any recommendations? I've looked on Amazon and there are so many recent titles and I can't work out whether they're part of a series or not!