The third book in the series. Spoilers aheads for NPCs and Split the Party.
It opens with Russell and his sister tracking down a booth at a convention. The booth has only a woman handing out modules to those on her list. Both of them are dumbfounded that he's on it; his sister admits for the first time she's starting to find it as weird as he does. Next chapter depicts our main team of NPCs deciding that, danger or not, the best route is to go into a city and find some quests to go on that will let them earn the gold they need for supplies. And the chapter after that depicts the three mean-spirited and vicious players from NPCs acquiring a new GM and so a new game, even if they find it a bit odd. (No one else will take them on, they're that bad.)
So all three groups head to this city. Through minor quests and the prospect of the Grand Quest. Russell grows more convinced that the text in the module is changing through adventures that turn on Eric's getting properly trained, Thistle's immunity to poison, a mission to gather berries, cleaning rats out of a cellar, negiotiating with a dragon, more of the artifact from before, and more. The whole interaction between our world and the game world looms larger, and we actually start to get glimpses of those behind it all.