Mordax et al

And there it might have ended. In fact it did end there, in millions of universes. Edward d’Eath grew older and obsession turned to a sort of bookish insanity of the gloves-with-the-fingers-cut-out and carpet slippers variety, and became an expert on royalty although no one ever knew this because he seldom left his rooms. Corporal Carrot became Sergeant Carrot and, in the fullness of time, died in uniform aged seventy in an unlikely accident involving an anteater.
In a million universes, Lance-Constables Cuddy and Detritus didn’t fall through the hole. In a million universes, Vimes didn’t find the pipes. (In one strange but theoretically possible universe the Watch House was redecorated in pastel colors by a freak whirlwind, which also repaired the door latch and did a few other odd jobs around the place.) In a million universes, the Watch failed.
In a million universes, this was a very short book.