Any Stephen King fan can tell you that most or all of King’s many books inhabit a strange and interconnected world that frequently has overlapping people, places, and things. It’s hard to really grasp how connected everything is until you look at something like this amazingly detailed flowchart tessiegirl assembled and posted on her site last month. She had made an earlier chart that excluded The Dark Tower. Since The Dark Tower series is the glue that binds pretty much everything else King together, having it included in this new version is an awesome addition.
If the text on the image is too small for you, you can buy the full chart as a printed poster from tessiegirl’s site (linked above).