It's a multipart archive. Parts 2 and 3 aren't supposed to be extracted separately, but as long as they are in the same folder as part 1, parts 2 and 3 should be extracted as well.Everytime i try to extract the part 2 or 3 of the chapter 3 it says that ''You need to extract the previous version of this volume'' But i already have extracted chapter 3 part 1