The order really doesn't seem to work. Chapter Six seems to take place between Chapters One and Two, and there are two Chapter Fours.
That said, these two at a haunted house is great fun.
The chapter 4 bit is a weird error, but the joke of Chapter 6 is that chapters 2 to 5(second4) are all a dream caused by 1, only for them to arrive to the same place the dream started.
My explanation came out kinda screwy, sorry.