Parmandur
Book-Friend
I assume it's "DM secrets" from the book, about what is really going on with the Radiant Citadel. But he also suggests that this connects to future books, and I wonder if that means more compilations with WotC, DMsGuild expansion material, or maybe the upcoming WotC books this year,, similar to how Candlekeep dovetailed well with Strixhaven...Huh? Good question.