If we assume the Patricians growing interest in the crossword puzzle lady, along with the surprising risks he has been taking, is a sign of growing instability, what would happen if he became too unstable? Consider all the known factors of Ankh Morpork. How would Vimes respond to it? Would carrot take the throne? What about Moist, the Ridcully brothers, and even Mrs. Cake?
Since this is all hypothetical, you can't be wrong.