One campaign I'm planning now, has the following Acts:
Act 1: Heroes of Loftgarten, Act 2: Revelation of Fate's Role, Act 3: Saviors of Throdin
General plot is that the players achieve some landmark achievements in Act 1, with many A plots available to choose from. In Act 2, they are faced with an existential secret that puts them at odds with the universe. In all cases, I'm considering this Act to be them ending up in a parallel world where they don't exist with clues to the fact that they don't belong in their world either; this is a B plot connecting to the plots of Act 1. By Act 3, they…