The lag between 3 and 4 was long. Then I got volume 4, picked it up, put it down, and then picked it up later an couldn’t put it down again. Out of all 7 of the books, Wizard and Glass and Wolves of the Calla are my favorite, and my favorite plot scene is the ultimate drawing of Jake through the mud door in The Wastelands.
May have to reconsider reading it. It has been so long I may just start with book one.